EFFECT OF CONFINEMENT ON COMPRESSIVE STRENGTH AND DUCTILITY OF CONCRETE USING DUCT TAPE AND POLYPROPYLENE STRAPPING BAND.
Prof: Dr. Bazid khan
Faculty of Engineering
CECOS University of Information Technology and Emerging Sciences Peshawar, Pakistan
The utilization of efficient and effortlessly accessible material for retrofitting or reinforcing inadequate solid sections perceptibly expanded in the previous couple of decades. A lot of research has been led on the conduct of bound round solid sections. In the present examination, the concentration was to explore the conduct of solid chambers that were fortified utilizing Duct Tape and Polypropylene Strapping Band. In the test segment of this examination, 21 solid chambers (6″ Diameter and 12″ high) were thrown and tried under compressive stacking. The examples were isolated into two arrangement i.e controlled examples and bound examples. In the principal arrangement, 3 solid chambers (un-restricted) were threw and tried following 28 days restoring period. Alternate arrangement of solid barrels were restricted by conduit tape and polypropylene tie band. One arrangement of solid chambers (set contain 3 barrels) were restricted by single layer of pipe tape and tried following 28 days restoring period. Also one arrangement of solid chambers were kept by twofold layer of channel tape and tried following 28 days relieving period. One arrangement of solid barrels were restricted by triple layer of pipe tape and went through under compressive stacking 28 days relieving period and the outcomes were noted. The plan was taken after for three arrangements of solid chambers which were totally limited by a solitary layer of polypropylene lash band and tried following 28 days restoring. An arrangement of 3 solid barrels were restricted by polypropylene lash band at finishes of chamber (at 6 creeps from the two closures) and tried while one arrangement of 3 solid barrels were bound by polypropylene on midriff just (at 6 inches area) and tried following 28 days restoring. Hence, the primary parameters considered in the present investigation were the solid compressive quality augmentation affected by number of layers by the binding material, sort of material and the time passed in the wake of spalling of solid barrel till disappointment of test. Those three parameters were used to explore the viability of the channel tape and Polypropylene lash band control in upgrading the hub stack conveying limit and malleability of the fortified segments. Test outcomes affirmed that the repression created by the channel tape and polypropylene tie band upgraded the hub stack conveying limit, vitality retention and time passed from spalling till disappointment if contrasted with unwrapped examples. What’s more, the outcomes demonstrated that a RC sections ought to be kept by more number of layers rather than a solitary layer of conduit tape so as to accomplish a critical upgrade in the execution of the fortified segments. Besides, the test outcomes showed that the viability of the polypropylene tie band as a restriction material was more articulated on account of additional time slip by between spalling of cement and its disappointment cautioning time.
Table of Contents
TOC o “1-3” h z u Chapter 1 (Introduction) PAGEREF _Toc516271946 h 101.1General PAGEREF _Toc516271947 h 101.2RC Columns, Confining Zone and Confinement PAGEREF _Toc516271948 h 111.3Requirement of Closely Spaced Ties in Confining Zone PAGEREF _Toc516271949 h 121.4Objectives PAGEREF _Toc516271950 h 131.5Organization of Thesis PAGEREF _Toc516271951 h 13Chapter 2 (Literature Review) PAGEREF _Toc516271952 h 142.1Previous Work PAGEREF _Toc516271955 h 142.2Duct Tape PAGEREF _Toc516271956 h 182.2.13MTM All Purpose Duct Tape DT8 PAGEREF _Toc516271957 h 192.3Strapping Band PAGEREF _Toc516271958 h 212.4Methodology PAGEREF _Toc516271959 h 232.4.1Raw Materials PAGEREF _Toc516271960 h 232.4.2Testing of Materials PAGEREF _Toc516271961 h 232.4.3Mix Design PAGEREF _Toc516271962 h 242.4.4Casting of Samples PAGEREF _Toc516271963 h 242.5Trial Batch Method of Concrete PAGEREF _Toc516271964 h 24Chapter 3 (Experimental Program) PAGEREF _Toc516271965 h 263.1Materials and Their Properties PAGEREF _Toc516271966 h 263.1.1Cement PAGEREF _Toc516271967 h 263.1.2Fine Aggregate PAGEREF _Toc516271968 h 273.1.3Coarse Aggregate PAGEREF _Toc516271969 h 303.1.4Flakiness and Elongation Index of Coarse Aggregate (ASTM D 4791) PAGEREF _Toc516271970 h 323.1.5Water PAGEREF _Toc516271971 h 333.2Concrete Mix Design (ASTM_211) PAGEREF _Toc516271972 h 333.3Tensile Strength of Confining Materials PAGEREF _Toc516271973 h 353.3.1Tensile Test (ASTM_D 3759) PAGEREF _Toc516271974 h 353.3.2Tensile Test of Duct Tape PAGEREF _Toc516271975 h 363.3.3Tensile Test of Strapping Band: PAGEREF _Toc516271976 h 383.4Tests on Fresh Concrete PAGEREF _Toc516271977 h 403.4.13.4.1 Slump Test (ASTM C 143) PAGEREF _Toc516271978 h 403.4.2Compressive Strength of Concrete PAGEREF _Toc516271979 h 413.4.3Concrete Cylinder Compressive Test without Confinement: PAGEREF _Toc516271980 h 423.4.4Concrete Cylinder Confined by Duct Tape 1-Layer PAGEREF _Toc516271981 h 443.4.5Concrete Cylinder Confined by Duct Tape 2-Layer PAGEREF _Toc516271982 h 473.4.6Concrete Cylinder Confined by Duct Tape 3-Layer PAGEREF _Toc516271983 h 493.4.7Concrete Cylinder Confined by PP Strap Band PAGEREF _Toc516271984 h 513.4.8Concrete Cylindrical Confined by PP Strap Band at Mid only PAGEREF _Toc516271985 h 533.4.9Concrete Cylinder Confined by PP Strap Band on ends PAGEREF _Toc516271986 h 553.5Concrete Ductility in Terms of Time PAGEREF _Toc516271987 h 57Chapter 4 (Discussion) PAGEREF _Toc516271988 h 594.1Discussion PAGEREF _Toc516271989 h 59Chapter 5 (Conclusion ; Recommendation) PAGEREF _Toc516271990 h 615.1Conclusion PAGEREF _Toc516271991 h 615.2Recommendations for Future PAGEREF _Toc516271992 h 61References PAGEREF _Toc516271993 h 63
List of Tables
TOC h z c “Table 3.” Table 3. 1: Chemical composition of ordinary Portland cement Bestway PAGEREF _Toc516314307 h 26Table 3. 2: Batch quantities per cubic meter of concrete PAGEREF _Toc516314308 h 34Table 3. 3: Recommended slumps for various types of concrete PAGEREF _Toc516314309 h 40Table 3. 4: Comparison of Compressive Strength of Control Specimens with confined samples PAGEREF _Toc516314310 h 57
List of Figures
TOC h z c “Figure 3.” Figure 3. 1: Concrete samples in molds PAGEREF _Toc516316523 h 34Figure 3. 2: Tensile strength of Duct Tape PAGEREF _Toc516316524 h 36Figure 3. 3: Load-Displacement curve of Duct Tape PAGEREF _Toc516316525 h 36Figure 3. 4: Load-Time curve of Duct Tape PAGEREF _Toc516316526 h 37Figure 3. 5: Stress-Time curve of Duct Tape PAGEREF _Toc516316527 h 37Figure 3. 6: Tensile Test of Strapping Band PAGEREF _Toc516316528 h 38Figure 3. 7: Polypropylene Load-Displacement graph PAGEREF _Toc516316529 h 38Figure 3. 8: Polypropylene Load-Time graph PAGEREF _Toc516316530 h 39Figure 3. 9: Polypropylene Stress-Time graph PAGEREF _Toc516316531 h 39Figure 3. 10: Standard concrete compressive strength graph PAGEREF _Toc516316532 h 42Figure 3. 11: Compressive strength of control specimen PAGEREF _Toc516316533 h 43Figure 3. 12: Load-Time Curve of Control Specimen PAGEREF _Toc516316534 h 43Figure 3. 13: Time-Displacement Curve of Control Specimen PAGEREF _Toc516316535 h 43Figure 3. 14: Time-Displacement Curve of Control Specimen PAGEREF _Toc516316536 h 44Figure 3. 15: Concrete Cylinder Confined by Duct Tape 1-Layer PAGEREF _Toc516316537 h 44Figure 3. 16: Load-Time Curve of Concrete Cylinder Confined by Duct Tape in 1 Layer PAGEREF _Toc516316538 h 45Figure 3. 17: Load-Displacement Curve of Concrete Cylinder Confined by Duct Tape Layer-1 PAGEREF _Toc516316539 h 45Figure 3. 18: Stress-Strain Curve of Concrete Cylinder Confined by Duct Tape 1-Layer PAGEREF _Toc516316540 h 46Figure 3. 19: Concrete Cylinder Confined by Duct Tape in 2 Layers PAGEREF _Toc516316541 h 47Figure 3. 20: Load-Time Curve of Concrete Cylinder Confined by Duct Tape in 2 Layers PAGEREF _Toc516316542 h 47Figure 3. 21: Load-Time Curve of Concrete Cylinder Confined by Duct Tape in 2 Layers PAGEREF _Toc516316543 h 48Figure 3. 22: Load-Time Curve of Concrete Cylinder Confined by Duct Tape in 2 Layers PAGEREF _Toc516316544 h 48Figure 3. 23: Concrete Cylinder Confined by Duct Tape Layer-3 PAGEREF _Toc516316545 h 49Figure 3. 24: Load-Time Curve of Concrete Cylinder Confined by Duct Tape in 3-Layers PAGEREF _Toc516316546 h 49Figure 3. 25: Load-Displacement Curve of Concrete Cylinder Confined by Duct Tape in 3-Layers PAGEREF _Toc516316547 h 50Figure 3. 26: Stress-Strain Curve of Concrete Cylinder Confined by Duct Tape in 3-Layers PAGEREF _Toc516316548 h 50Figure 3. 27: Concrete Cylinder Confined by 1-Layer PP Strap Band PAGEREF _Toc516316549 h 51Figure 3. 28: Load-Time Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band PAGEREF _Toc516316550 h 51Figure 3. 29: Load-Time Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band PAGEREF _Toc516316551 h 52Figure 3. 30: Stress-Strain Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band PAGEREF _Toc516316552 h 52Figure 3. 31: Concrete Cylinder Confined by 1-Layer PP Strap Band at Center PAGEREF _Toc516316553 h 53Figure 3. 32: Load-Time Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at center PAGEREF _Toc516316554 h 53Figure 3. 33: Load-Displacement Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at center PAGEREF _Toc516316555 h 54Figure 3. 34: Load-Displacement Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at center PAGEREF _Toc516316556 h 54Figure 3. 35: Concrete Cylinder Confined by 1-Layer PP Strap Band at both ends PAGEREF _Toc516316557 h 55Figure 3. 36: Load-Time Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at both ends PAGEREF _Toc516316558 h 55Figure 3. 37: Stress-Strain Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at both ends PAGEREF _Toc516316559 h 56Figure 3. 38: Displacement-Time Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at both ends PAGEREF _Toc516316560 h 56Figure 3. 39: Time-wise elasticity of different confining materials PAGEREF _Toc516316561 h 58Figure 3. 40: Compressive strength of concrete PAGEREF _Toc516316562 h 58
KEY TO SYMBOLS AND ABBREVIATIONSACI=American concrete institute
ASTM=American society for testing and materials
W/C=Water to cement ratio
OPC=Ordinary Portland cement
*Refers to critical value
Chapter 1 IntroductionGeneralConcrete is the most generally utilized development material; its utilization by the networks over the globe is second just to water. Generally, concrete is created by utilizing the Ordinary Portland Cement (OPC) as the cover. The use of OPC is on the expansion to meet framework improvements. The overall interest for OPC would increment promote later on. The solid center extends along the side when it is subjected to a pivotal pressure stack. This extension of the solid center is limited by steel tying down, FRP (Fiber Reinforced Plastic) coats or shells and steel strips, to make the solid center ready to take more loads. Contrasted and other strengthened cement (RC) sections, restricted solid segments act extraordinarily when subjected to a pivotal pressure stack
The 1971 San Fernando tremor, the 1987 Whittier seismic tremor, and the 1989 Loma Prieta quake exacted considerable harm on various more seasoned structures. One of the significant reasons for the segments disappointment was the substandard enumerating of those basic segments outlined before the current seismic plan arrangements had been received. The deficient itemizing of these structures has brought about numerous scaffolds and structures having segments with low flexural quality, low shear quality, and low flexural flexibility. The lacking starter bar lap lengths and inadequate parallel ties in these sections are the real supporters of their deficiency in opposing tremor powers.
Crafted by numerous analysts has demonstrated that expanding the constrainment in the potential plastic pivot districts of the segment will build the compressive quality of the center concrete and extreme solid pressure strain and pliability. Subsequently, fortifying procedures regularly include strategies for expanding the limiting powers either in the potential plastic pivot areas or over the whole segment.
Segment disappointments in late tremors, for example, the 1989 Loma Prieta quake have pulled in the consideration of the building network to the vast number of structures with substandard seismic outline subtle elements. Numerous solid sections planned before the new seismic outline arrangements were embraced have low flexural flexibility, low shear quality, and insufficient lap length for starter bars. These issues, exacerbated by defects in the outline of auxiliary frameworks, have contributed numerous segment disappointments in ongoing tremors. This issue pulled in the consideration of building network to retrofitting and imprisonment strategies were produced. The retrofitted segments withstood in 1994 Northridge seismic tremors with no harm (Loud 1995).
In this examination, another strategy for seismic reinforcing of solid segments is exhibited. Segments in existing structures are remotely strengthened by methods for Duct Tape and Poly Propylene Strapping Bands. The fortification is performed by folding ties of wanted width and thickness over the segments. The ties can be enclosed by a ceaseless winding or potentially in intermittent rings. The ties are developed from high-quality strands woven to shape an adaptable texture like material. The textures can be made thin, bringing about adaptability adequate for them to be folded over round and in addition rectangular sections. For enhanced basic execution and additionally assurance against natural factors, the ties can be impregnated with sap either previously or after the wrapping task. The closures of the lashes is coupled to the segment because of its very staying power.
RC Columns, Confining Zone and ConfinementStrengthened cement (RC) is broadly utilized for development everywhere throughout the world. Segments exchange the heaps from pillars and pieces to establishments. Segments bolster high compressive powers in uber structures, for example, long-traverse structures and tall structures. Also, sections may endure harm because of over-burdening and catastrophic events, for example, quakes and flames in view of the constrained quality and pliability of cement.
Segments are essential auxiliary part subjected to for the most part pivotal powers with or without the minute whose disappointment prompts crumple of a structure. Under the utilization of load, segment abbreviates longitudinally and grows horizontally. This horizontal development is articulated when the burdens surpass 70% of section quality. On utilization of greatest hub stack, the solid pulverizes and the longitudinal support clasps outwards.
Confinement of solid alludes to the strategy that connected in such way that it “limits” the solid center of a fortified solid section to support compressive strains and to supply expanded quality and diversion capacities. So also imprisonment zone in a segment is where littler separating of stirrups is required for higher pliability.
Compressive strains caused by sidelong misshapening are added substance to the strains caused by the hub stack. It takes after that confinement support ought to be expanded with the hub load to guarantee predictable parallel disfigurement limit. The reliance of the measure of required restriction on the extent of the pivotal load forced on a segment has been perceived by a few codes from different nations, (for example, Canada’s CSA A23.3-14 and New Zealand’s NZS 3101-06) however was not reflected in ACI 318 through its 2011 release.
In 1978, Sheik and Uzumeri uncovered that both the quality and flexibility of segments are enhanced by appropriating the longitudinal support bars around the center border and restricting these bars with laterals, for example, ties. Thusly, both longitudinal and horizontal fortifications are basic for RC sections. While the solid center is subjected to outspread pressure in the level course, the keeping volume is subjected to loop strain. Notwithstanding, either the vast dispersing or close separating between ties brings about absence of constrainment of solid center. While low volumetric proportion of ties decreases the restriction of solid center, high volumetric proportion of ties surrenders solid progression and makes a feeble plane between the center and the solid cover other than making development issues because of the clog of segment confine with fortification. Welded fortification frameworks were utilized by Saatcioglu and Grira and Kusuma et al. to decrease support clog because of covering circles, twists and twist expansions.
Requirement of Closely Spaced Ties in Confining ZoneBeing a particularly delicate material, bond can without quite a bit of a stretch split if there ought to emerge an event of utilization of strain stack. In the midst of tremor the sustained strong part’s demand is additions than as far as possible. In this way it done intentionally to scatter seismic tremor imperativeness going into the functioning as hysteresis essentialness twists where a section encounters different cycles of reversible stacking.
In the midst of tremors or in case of occasion of sidelong contortion in light of some reason, around then portion experiences most prominent minutes at its completions. These segment end zones goes under most outrageous non linearity to the extent stress and strains. By and by, concrete can’t pass on this much measure of strains in weight and therefore it requires a consistent part to deal with the load and fulfill its inspiration. That solid part is the immovably isolated ties. These ties in the locale of high moment zone (a confining area) accomplishes required pliability and it furthermore overhauls the execution of bond.
ObjectivesThe goals of this preliminary program are according to the accompanying.
i.To investigate the most sensible and basic approach of repairing, and retrofitting of strong structures.
ii.In the case of structures which have not been hurt starting at now, to improve its capacity of passing on stack, and to upgrade its withstanding shudder hurts.
iii.To consider the effect of pipe tape and PP Strap Band as a confining material around concrete.
iv.To investigate the effects of pipe tape layers and PP tie band constraining territory upon compressive nature of bond.
Organization of ThesisPostulation work comprise of five parts in which distinctive parts of cement related with importance of work will be talked about. To start with part comprise of prologue to the postulation title and points of interest of destinations and extent of our examination work. Second part is about the past work (writing survey) that is finished by other specialist are explored in detail. Third section manages the choice of materials and philosophy utilized the in exploratory work and its outcomes. Fourth section manages discourse of different exploratory work done and proposals. Fifth part makes inferences from the examination.
Previous WorkAccomplishing the essential approach of this examination, and to comprehend the past endeavors, detail survey of writing is done which incorporate the audit of course books, scholarly diaries and periodicals, look into papers and classes. The repression innovation of RC Column and its advancement in this day and age with a detail foundation information is introduced in this section. A large portion of the accessible distributed writings on constrainment of RC segments are quickly evaluated.
Chai et al. (1991) introduced outer control of sections with (steel jacketing) to enhance the shear quality and flexibility of segments. To examine the execution of the segments retrofitted with steel jacketing, six huge scale segment models were tried at the University of California at San Diego. The segments were 0.4-scale models of a model 1524-mm-(60-in.)- distance across connect segment. They were 610 mm (24 in.) in measurement and 3657 mm (12 ft) in stature. The test sections were built with a balance to permit establishment impact or association to be checked. The tests included models with the pre-1971 fortifying points of interest without retrofitting, sections retrofitted with steel coats, and a post-harm retrofitted segment to decide if a harmed segment can be rescued after a tremor. The longitudinal steel stronghold extent was 2.53 percent. Transverse help contained circuitous circles (No. 2 Grade 40 plain bars) put at 127 mm (5 in.) on concentrates reliably along the longitudinal line of the fragment. The limiting steel bolster extent was 0.18 percent. The circles were united with a lap length of 305 mm (12 in.) in the cover concrete. Steel coats for the portions were produced from 4.76-mm-(3/16 – in.)- thick A36 hot-moved steel. A 6.3-mm (1/4-in.) opening was given between the area and coat. The opening was weight mixed with water/bond grout. From the test results, it was assumed that a lap length of 20 times the longitudinal bar width was insufficient to make yield stress of the longitudinal bars; areas without retrofitting corrupted rapidly as a result of security disillusionment. The detainment gave by a totally grouted steel coat could absolutely contain the cover concrete to get rid of bond dissatisfaction. In like manner, in light of the way that there was only a 10 to 20 percent extension in level solidness due to additional control from the steel coat, a bendable strategy for flexural dissatisfaction with extraordinary imperativeness dispersal could be refined. The steel coat enabled a dislodging flexibility factor of more significant than 6 to be proficient.
Mirmiran, and Shahawy (1997) introduced another procedure for concentrate the conduct of kept solid segments. As per their work outer repression of cement by methods for high-quality fiber composites can essentially upgrade its quality and pliability and additionally result in substantial vitality ingestion limit. The repression component may incorporate fiber-wrapping of existing segments as a retrofitting measure or encasement of cement in a fiber fortified plastic (FRP) tube for new development. A sum of thirty solid chamber (6x12in) were tried, which incorporate 24 concrete filled FRP tubes and six plain solid examples. Three groups of cement with various target qualities and water-to-concrete proportions were utilized as a part of the investigation. No added substance was utilized as a part of any of the blends. For each clump, three unmistakable coat thicknesses of 6, 10 and 14 layers were tried. Two unconfined control examples were set up for each group. FRP tubes comprised of a fiber wound edge handle of polyester pitch with unidirectional E-glass filaments at ±15° winding point. Uniaxial pressure tests on concrete-filled FRP tubes shows that fiber composites are a powerful methods for imprisonment, as they altogether increment both quality and malleability of cement.
So also another investigation was made on the compressive conduct of cement kept via carbon fiber composite coats by Xiao and Wu (2000). In this work hub pressure test consequences of 27 solid barrels kept via carbon fiber fortified polymer composite coats were portrayed. The test parameters incorporate plain cement compressive quality and the thickness of the composite coat. An aggregate of 36 solid barrels with a distance across of 6 in. What’s more, a stature of 12 in. Were built and tried under hub pressure. Three clumps of cement speaking to lower, medium, and higher quality cement were readied. The greatest size of the coarse totals was around 13 mm (around 0.5 in.). The objective qualities at 28 days for the lower, medium, and higher quality cement were 27.6 mpa (4 ksi), 37.9 mpa (5.5 ksi) and 48.2 mpa (7 ksi), individually. The real solid qualities at testing ages around 60 to 80 days in the wake of throwing were somewhat higher than the blend configuration target qualities. For each bunch of solid, 12 chambers were thrown in plastic barrel jars utilizing the standard methodology. The examples were restored in a nearby can condition at room temperature. Three chambers from each bunch were tried without jacketing to give control information to the unconfined cement, and nine others were wrapped with composite coats at three distinct kinds of thickness. For every mix of testing parameters, three indistinguishable examples were manufactured and tried. The completions of the strong barrels were finished with great sulfur. The edge of the sulfur was trimmed remembering the true objective to keep the composite coat from direct bearing the center point weight. A thin layer of basis epoxy was first associated with the strong surface. After the foundation epoxy on the strong surface was calmed at the encompassing temperature for a couple of hours, the carbon fiber sheets were presented in 1-layer, 2-layer, and 3-layer to Low medium and high strong cases. For each layer of carbon fiber sheet, two layers of epoxy, one on the chamber surface going before presenting the sheet and the other on the surface of the presented sheet, were associated using paintbrushes or rollers to totally splash the layers with epoxy. The extra epoxy for each layer was smashed out to consolidate the coat. After the required layers of the sheet were presented, the CFRP composite coat was mitigated in the including condition. Consequent to testing the illustrations It is found that the carbon fiber composite jacketing can basically manufacture the compressive quality and malleability of concrete. Other than the material properties, for instance, strong quality, the execution of the restricted bond is ordered by the restraint modulus. A complete condition of the bound concrete is controlled by the split of the composite coat.
Moghaddam et al. (2009), displayed preliminary and demonstrative examination of bond kept by external pre-concentrated on strips (metal strips). Their work generally revolve around the preliminary and consistent examination on the use of lashing framework for retrofitting of strong segments. Exploratory program included vital compressive tests on barrel formed and multicolored little scale sections which were adequately bound by pre-concentrated on metal strips. The material used for the strong illustrations included form I Portland bond, neighborhood sand and shake. The best size of the stone was 12 mm. No additional substance was used as a piece of any of the mixes. Preliminaries included 25 round and empty and 15 vivid strong cases. The fragment models were made of a by and large top notch concrete with no air-entrainment. The strong accomplished an ordinary uniaxial compressive nature of around 50 MPa. The illustrations were ousted from the structures following 2 days and put into water to be wet calmed. The tube formed and multicolored cases were had a go at following 428 days in the wake of tossing. Two sizes of metal strips were used for sustaining of the illustrations. The cases were sustained by using 16 × 0.5 mm and 32 × 0.8 mm strips. After the strong fragment models had been reestablished, the metal strips were lashed around the cases. Vital weight tests were coordinated using a testing machine with a breaking point of 1,780 KN (400 kips). The compressive tests were coordinated on the illustrations. The essential load, with a store rate of 178 KN/min, was extended monotonically until the point that the illustrations failed. This stacking rate is practically identical to 0.25 MPa/sec. The ASTM standard stacking rate for compressive nature of round and empty strong illustrations is inside the extent of 0.14– 0.34 MPa/sec. Thusly, picked stacking rate falls inside the extent of the ASTM standard. The associated technique for fortifying of strong sections could fabricate quality, adaptability of concrete widely. The procedure could grow the zenith quality and its contrasting strain of concrete up with 230 percent. The get in flexibility of constrained concrete was outstandingly unstable to the malleability of the metal strip used. Dynamic detainment realized better change of value and adaptability of bound concrete than segregated constrainment. The profitability of constrainment in barrel molded cases, i.e. the get in quality and flexibility, was more important than that of colorful ones.
Smith et al. (2010), made a trial examination on the quality and conduct of extensive 250 mm measurement concentrically stacked unreinforced fiber-strengthened polymer FRP kept solid barrels. In this examination, the impact of the quantity of layers of the FRP and diverse cover areas on the adequacy of the FRP wrap was resolved. Irregular versus constant wrapping setups to keep the barrel are additionally examined. The exploratory program comprised of testing six substantial plain unreinforced solid barrels under monotonically expanding concentric hub stack. All chambers were ostensibly 250 mm in measurement and 500 mm in stature of which one barrel filled in as a control (unwrapped) and five were wrapped with two layers of carbon-FRP CFRP. One example was tried for every design as it was the goal of this investigation to see in detail the particular example conduct. The five diverse wrapping courses of action embraced with the two principle factors being (1) coherence of the fiber sheets per barrel i.e., one constant sheet or two separate sheets and (2) the area of the cover. As an outcome of the cover plans, the wrapped chambers were restricted with two layers of FRP in the non-cover districts and three to four layers in the cover areas. In the wake of testing the disappointment stack for control example was 35 MPa while for External FRP layer end in two-layered area, Two-layered district, Three-layered (cover) locale, Internal FRP layer end in two-layered locale, External FRP layer end in two-layered area are 43MPa, 50 MPa, 57 MPa, 59 MPa, 56 MPa individually. The aftereffects of an exploratory program demonstrated the conduct and viability of FRP enclosing by the constrainment of substantial concentrically stacked solid chambers. Every single limited barrel were found to flop by break of the FRP, as not out of the ordinary.
Duct TapeConductor Tape is a polyethylene, multi-reason, fortified, weight unstable tape. It has a fragile and semi-versatile shell and weight unstable paste. The tape ordinarily comes in silver/diminish or dull, at any rate extraordinary tones are available. The tape is water safe and can hold up in numerous conditions. Pipe Tape was given its name as it can rebuff water and thusly interfaces with the phrase and reference “like water off a duck’s back”.
Figure 2. SEQ Figure_2. * ARABIC 1: 3M Duct Tape3MTM All Purpose Duct Tape DT8Product Description:
3M™ All Purpose Duct Tape DT8 is a 8 mil pipe tape with a built flexible concrete and water safe polyethylene backing. It gives basic tear and awesome similarity. The fabricated flexible bond settles on it an unprecedented choice for holding fast to metal, glass, plastic, settled cement and that is only the start.
Backing: Polyethylene Film over Cloth Scrim
Standard Roll Length:60 yards (179.74 ft)
Typical Physical Properties:
ASTM Test Method
Grip to Steel 100 oz./in. width (109.4 N/100 mm) D-3330
Malleable Strength31 lbs./in. width (542 N/100 mm width) D-3759
Stretching at Break21% D-3759
Tape Thickness:8.0 mils (0.2 mm) D-3652
Aggressive designed flexible paste gives minute connection to a wide collection of surfaces including metal, glass, plastic, and settled bond.
Woven texture scrim empowers the tape to tear easily by hand and gives effortlessness of use and managing.
Tightly woven scrim gives high flexibility which is ideal for bundling applications.
Great Quick Stick.
Holding and bundling applications for a wide collection of materials and substrates.
Marking and Labeling.
Store under ordinary states of 60ºF to 80ºF (16ºC to 27ºC) and 40 to 60% R.H. in the first container.
To obtain best execution, use this thing inside multiyear from date of manufacture.
The most outrageous quiet that pipe tape can be used as a piece of is 200 degrees Fahrenheit. It is troublesome for the paste to append to a challenge that is too much hot. Pipe tape also has a troublesome time holding with anything lower than 20 degrees Fahrenheit.
The common thickness of channel tape is 8.5 mils or 10.7 milli-inch. The thickness of the channel tape will conclude that it is so normal to work with. The thicker the tape, the more troublesome it will be to wrap and bend it around objects.
Strapping BandPolypropylene tie is a saving material expected for light to medium commitment unitizing, palletizing and bundling. It is open in various widths, thicknesses, and polymer assortments (e.g., copolymers). This thing offers higher prolongation at break yet tends to have sad dead stretch with unfaltering weight.
Polypropylene tying may be printed, either in the midst of age and pre-adorning for the most critical quality and exactness, or after creation over the enlivening for a reduced quality. Both offer security and promoting positive conditions to the lashed thing.
Lashing gatherings engage lively and bother free tying on manual mechanical assemblies or on self-loader or customized machines working at quick. Tying gatherings can be related by metal or plastic locks or by ultrasound or warmth welding. One of the advantages of plastic lashing band is the low weight, acclimation to the kind of squeezed dissent, deterrent against soddenness and the larger part of general manufactured substances; they don’t expend. Packaging band completing is settled by the sticky tape.
Figure 2. SEQ Figure_2. * ARABIC 2: Polypropylene Strapping BandsProduct Description:
GRANOFLEX® is the enlisted exchange name for monoaxial-situated expelled lashing groups made of polypropylene (PP).
Unobjectionable for condition, recyclable, lashing gatherings can be put away in dumps or combusted – no damaging substances appear.
Contact With Food Stuff:
Application for coordinate contact with foodstuff isn’t prompted.
Manual or machine tying of items
Safety fixing of the products for transport
Packaging products in packs
Tying band twisted on center.
White, dark, yellow, red, blue, green.
Width 5 – 19 mm
Thickness 0.35 – 0.90 mm
Minimal Tensile Strength:
560 – 4000 N
10 – 25 %
Inside Ø 60, 150, 200, 280, 400, 407 mm
Winding On Reel:
Winding length 900 – 7300 m
The two sides emblazoning
To accomplish the goals the investigation will center around the accompanying errands.
Raw MaterialsThe locally accessible customary Portland concrete, fine total, coarse totals and faucet water will be utilized.
Testing of MaterialsAll materials will be tried by ASTM models.
Sieve examination of coarse and fine total (ASTM C 136)
Fineness modulus of coarse and fine total (ASTM C 33)
Water ingestion and particular gravity of coarse total (ASTM C 127)
Water ingestion and particular gravity of fine total (ASTM C 128)
Bulk thickness of coarse and fine total (ASTM C 29)
Flat and Elongated Particles in Coarse Aggregate (ASTM D 4791)
Tensile Strength of Duct Tape and PP Strap Band (ASTM D 3759)
Mix DesignUtilizing the information from materials, testing, blend configuration will be completed for an objective quality of 15 MPa. Extent of fixings found from the blend configuration will be utilized as a part of getting ready solid blend.
Casting of Samples57 Cylinders having size 6″x12″ will be gave a role according to ASTM_ C192 determinations. Three arrangement of tests will be readied and each compose will comprise on nine chambers. One arrangement will have no tape control and will be utilized as reference barrels for correlation with the consequences of bound chambers. Second arrangement of barrels will be restricted by channel tape with single layer, twofold layers and triple layers. Third arrangement of Cylinders will be limited by Polypropylene tie band with single layer, single layer at mid part of chamber and single layer at the two finishes of barrel.
Barrels will be put at compressive test following 28 days curing and the test aftereffects of the kept example will be contrasted and reference examples. ASTM_C39 will be taken after for compressive testing. Three barrels of every classification will be tried and a normal esteem will be taken as compressive quality.
Trial Batch Method of ConcreteThe water-concrete proportion might be chosen from the data or any appropriate bend as in Fig.2.3 and a few little preliminary bunches with changing measures of totals are delivered to get the coveted quality, consistency and different properties with least measure of glue. The consistency of cement is most as often as possible estimated by droop test.
w/c for Normal Concrete: 0.4 to 0.6
w/c for High Strength Concrete: As low as 0.21
611505571500Figure 2. SEQ Figure_2. * ARABIC 3: Impact of Water-Cement Ratio on multi day Compressive and Flexural rigidity
Chapter 3Experimental ProgramIn light of past work of the Publisher over restriction of cement, a definite test work is directed keeping in mind the end goal to build up another strategy for seismic fortifying of solid segments and to make it more malleable. In this part, a detail summery of getting ready limited solid examples as per the arrangement of ASTM measures and after that outcomes are contrasted and the control examples. As indicated by ACI 211 blend plan for ordinary or control blend were readied, at that point utilizing diverse lashes as a keeping material to examine the impact of imprisonment material over solid examples.
Materials and Their PropertiesCementGenerally basic open bond in exhibit is Ordinary Portland concrete (OPC) which are of different sorts. Concrete with the Local brand name of Bestway bond stamp diminish in shading was used. It contains backhanded 67% CaO. It fits in with the ASTM C-150, BSS 12-1958 or PSS 232-1983 (R) and Pakistan Standards PS 12-1991.
Table 3. SEQ Table_3. * ARABIC 1: Chemical composition of ordinary Portland cement BestwayCompound Percentage ASTM (%) Range
SiO2 20.15 21-22
Al2O3 4.91 < 6
Fe2O3 3.38 0.5-6
MgO2.64 < 2
K2O 0.73 0.5-1.5
SO3 2.36 1.5-2.5
CL 0.005 < 0.10
The bond utilized was privately created conventional Portland concrete (Bestway Cement Company) meeting the prerequisites of ASTM C150. Allude annexure-I for the concrete test report utilized as a part of this trial program.
Fine AggregateThe sand used in the research was obtained from the nearby local suppliers. To check its suitability it was subject to the following tests.
Fineness Modulus of Fine Aggregate (ASTM C 33)Fineness modulus can be described as the correct regard that is the total rate held gained from a foreordained plan of sifter divided by 100. This test approach is utilized to pick the fineness modulus of the given fine grained illustration. In actuality, it is the single observational regard that is proficient from the sifter examination comes to fruition.
Data got from FM is important from various perspectives.
Fineness modulus gives facilitate information whether the material is particularly assessed or opening assessed.
Fineness modulus shows a general idea whether the material is fine or coarse.
It in like manner demonstrates the surface domain of the particles.
Surface Area = 1/(fineness Modulus)
Lower the surface region of the fine total, the required measure of new concrete glues to cover the total particles will be less and therefore less water is required.
Bigger estimation of FM is favored for fine totals.
For a decent fine total, the FM ought to be in scope of 2.3 to 3.1 (ASTM Range for fine totals).
Following method is received for assurance of fineness modulus:
Get ready test tests from an expansive load of total.
Strainer the example progressively on an arrangement of fitting sifter arranged by expanding fineness beginning from the biggest size.
After fruition of sieving, weigh deliberately the deposit or material held on each sifter starting with that which has passed the best strainer.
The FM is computed by the condition given beneath:
Fineness Modulus= (Sum of cummulative %age weight held on strainer # 100)/100
Strainer investigation was done to decide the grain measure dispersion, subsequently the fineness modulus.
Fineness modulus demonstrates the relative fineness of totals. It is a trial number used to characterize the fine totals. The estimation of fineness modulus changes from 2.3 to 3.1. Allude annexure-iii for the FM of fine total utilized as a part of this trial program.
Specific Gravity and Water Absorption of Fine Aggregate (ASTM C 128)Specific Gravity of a substance is the extent of the largeness of the given volume of substance, to the weight of equivalent volume of refined water removed at a temperature of 4oC.
As an adjacent gauge, non-refined water at room temperature may be used without physically affecting the results. Learning of specific gravity of aggregate is basic for a strong technologist choosing the properties of concrete delivered utilizing such aggregate.
Distinctive specific gravities for fine aggregate were registered using the underneath conditions:
Mass Specific Gravity (Oven Dry) = D/(C-A+B)
Water Absorption = (C-An)/Ax100
Weight of water + sample=A gm
Weight of water +vessel=B gm
Weight of sample=C gm
Weight of broiler dry sample=D gm
Allude annexure-iv for the genuine particular gravity and water retention of fine total utilized as a part of this exploratory program.
Bulk Density of Fine Aggregate (ASTM C 29)The mass thickness of the greatness of material in a given volume and is evaluated in lbs per cubic feet. The mass thickness for an aggregate is affected by a couple of factors including the measure of clamminess present and measure of effort displayed in working holders. The explanation behind test is to take a gander at properties of changed sums. The data of mass thickness of aggregate associates in preparing the weights of sums in mix design.
Technique for Bulk Density in Compacted State
Fill the chamber in three layers giving 25 hits to each layer.
Level the surface of barrel with the assistance of temping pole and expelling additional particles.
Take weight of total in compacted state.
Compute the mass thickness by the condition demonstrated as follows.
Mass Density=(weight of total)/(volume of total)
Strategy for Bulk Density in Loose State
Fill the barrel in three layers.
Level the surface of barrel with the assistance of temping pole and expelling additional particles.
Take weight of total in free state.
Compute the mass thickness by the condition given underneath.
Mass Density=(weight of total)/(volume of total)
For mass thickness of fine total utilized as a part of this trial program allude annexure-v
Coarse AggregateBeat stones secretly procured from a building site in Hayatabad (Peshawar) has been used with a mix of 1″ down and 1/2″ down. The traverse of coarse aggregate depends on work. The coarse aggregate used as a piece of this exploratory examination was a blend of 3/4″, 1/2″ and 3/8″ sizes.
Specific Gravity and Water Absorption of Coarse Aggregate (ASTM C 127)Specific Gravity of a substance is the extent of the greatness of the given volume of substance, to the weight of proportionate volume of refined water removed at a temperature of 4oC.
As a close-by estimation, non-refined water at room temperature may be used without substantially affecting the results. Data of specific gravity of aggregate is essential for a strong technologist choosing the properties of bond delivered utilizing such aggregate.
The specific gravity for coarse aggregate was processed using following game plan of conditions:
Mass Specific Gravity (Oven dray) = D/(C-A+B)
Weight of vessel +weight of soil +weight of water=(A)
Weight of water +vessel=(B)
Weight of SSD Coarse =(C)
Weight of broiler dry sample=(D)
Allude annexure-vi for the particular gravity and water retention of coarse total utilized as a part of this trial program.
Bulk Density of Coarse Aggregate (ASTM C 29)Mass thickness of aggregate is the mass of a unit volume of mass aggregate material, in which the volume consolidates the volume of the individual particles and the volume of the voids between the particles. Conveyed in kg/m3 (lb/ft3). The mass thickness of the largeness of material in a given volume and is evaluated in lbs. per cubic feet. The mass thickness for an aggregate is affected by a couple of parts including the measure of moistness present and measure of effort displayed in working compartments. It depends upon the squeezing of aggregate i.e. either inaccurately squeezed sums or well thick compacted sums. In case, if the specific gravity of material is known, by then it depends upon the shape and size of particles. It is by virtue of, if each one of the particles are of same size than squeezing ought to be conceivable up to an amazingly compelled degree. In case the extension of more diminutive particles is possible inside the voids of greater particles than these smaller particles enhance the mass thickness of the squeezed material. Condition of the particles also affect comprehensively, in light of the way that closeness particles depends upon the condition of aggregates.
A coarse aggregate with higher mass thickness, by then it suggests few of the voids can be filled by using fine sums and bond. For testing, British Standard (BS 812) has demonstrated the level of compaction.
The purpose behind test is to consider properties of different aggregates. The data of mass thickness of aggregate helpers in enlisting the weights of sums in mix diagram.
Method for Bulk Density in Compacted State
Fill the chamber in three layers giving 25 hits to each layer.
Level the surface of chamber with the assistance of temping pole and expelling additional particles.
Take weight of total in compacted state.
Compute the mass thickness by the condition demonstrated as follows.
Mass Density=(weight of total)/(volume of total)
Strategy for Bulk Density in Loose State
Fill the chamber in three layers.
Level the surface of chamber with the assistance of temping bar and expelling additional particles.
Take weight of total in free state.
Compute the mass thickness by the condition given beneath.
Mass Density=(weight of total)/(volume of total)
For mass thickness aftereffects of coarse total utilized as a part of this test program allude annexure-vii.
Flakiness and Elongation Index of Coarse Aggregate (ASTM D 4791)Add up to partials are said to be flaky when they have thickness under 0.6 times of the more significant estimation and the flakiness list (FI) is the rate by weight of flaky particles in an illustration, while on the multifaceted nature the drawn out particles are those whose more noticeable estimation is more than 1.8 times its mean size while the augmentation document (EI) insinuates the rate by weight of broadened particles in a sample.BS-1241 decides a flakiness record not outperforming 30% paying little respect to add up to measure. The barrel for the test should be picked by the aggregate size decided for the test, and the material utilized as a part of the test must be stove dried. Strainer examination is performed for a known measure of aggregate, after that a measure of aggregate hung on solitary sifter is weighed and for flakiness the held material is experienced a space of the predefined thickness along the thickness on legitimate opening of the check, and for the extending rundown of the aggregate the held material is checked autonomously for the length long measure. The weight should be recorded for the material which passes the thickness of the measure for the flakiness test while the material which does not experience the length check is recorded for the extending test.
The flakiness and expansion record was figured using underneath conditions: Most extreme allowed lengthening list is 35,40 or 45% for total size 2 1/2″
– 2”, 1 ½” – ¾” and ½” – 3/8”
Both Flakiness and Elongation tests are not relevant to sizes littler then 6.3mm i.e. ¼” strainer.
Allude annexure-viii for the aftereffects of flakiness and lengthening list of coarse total utilized as a part of this test program.
WaterFaucet water was utilized all through the trial work. The capacity of water in concrete is to respond synthetically with bond frame the coupling glue for mortar and coarse total. It empowers the solid blend to stream into formwork.
Concrete Mix Design (ASTM_211)The strategy for decision of mix degrees given in this section is apropos to conventional weight concrete.
Despite whether the strong traits are suggested by the subtle elements or are left to the individual picking the degrees, establishment of bunch weights per m3 of bond can be best refined in the going with gathering through a formal mix diagram.
Mix diagram in this endeavor was finished by ACI 211 for 15MPa Compressive Stress with following genuine advances:
Stage 1. Choice of hang
Stage 2. Choice of most outrageous size of aggregates
Stage 3. Estimation of mixing water and air content
Stage 4. Assurance of water bond extent
Stage 5. Check of bond content
Stage 6. Estimation of coarse aggregate substance
Stage 7. Estimation of fine aggregate substance
Stage 8. Changes of aggregate clamminess
Stage 9. Fundamental bunch modifications
Allude annexure-ix for the detail blend plan count and results utilized as a part of this trial program.CEMENT : FINE AGGREGATES : COARSE AGGREGATES
271.5: 794.326 : 1073.05
1: 2.92: 3.95
Table 3. SEQ Table_3. * ARABIC 2: Batch quantities per cubic meter of concreteMaterials Batch Weights (Kg/m3)
Fine Aggregate 794.326
Coarse Aggregate 1073.05
Figure 3. SEQ Figure_3. * ARABIC 1: Concrete samples in moldsTensile Strength of Confining MaterialsThe fundamental idea of a flexible test is to put a case of material between two devices called “holds” which prop the material. The material has known estimations, like length and cross-sectional zone. After that apply weight to the material toward one side while the contrary end is settled. We keep growing the weight (habitually called the load or power) while meanwhile assessing the modification long of the case.
Tensile Test (ASTM_D 3759)Measure the adjustment long while including weight until the point when the part starts to extend lastly breaks.
The consequence of this test is a diagram of load (measure of weight) versus dislodging (sum it extended). Since the measure of weight expected to extend the material relies upon the span of the material (and obviously the properties of the material), examination between materials can be extremely testing. The capacity to influence a legitimate correlation with can be essential to somebody outlining for basic applications where the material must withstand certain powers.
We require a method for straightforwardly having the capacity to look at changed materials, making the “quality” we report free of the span of the material. We can do that by basically isolating the heap connected to the material (the weight or power) by the underlying cross-sectional zone. We additionally separate the sum it moves (dislodging) by the underlying length of the material. This makes what material researchers allude to as designing pressure (stack isolated by the underlying cross-sectional zone) and building strain (relocation partitioned by beginning length). By taking a gander at the building pressure strain reaction of a material we can think about the quality of various materials, autonomously of their sizes.
Tensile Test of Duct Tape80010049974500
Figure 3. SEQ Figure_3. * ARABIC 2: Tensile strength of Duct Tape019558000
Figure 3. SEQ Figure_3. * ARABIC 3: Load-Displacement curve of Duct TapeFigure 3.3 shows the behavior of the duct tape when load applied on it. It shows that the duct tape; loose its strength, upon applying loads.
Figure 3. SEQ Figure_3. * ARABIC 4: Load-Time curve of Duct TapeThe graph in figure 3.4 indicates that, beside that the duct tape has low tensile strength; it has very high elasticity.
Figure 3. SEQ Figure_3. * ARABIC 5: Stress-Time curve of Duct TapeThe graph in figure 3.5 indicates that the maximum stress applied on Duct tape is 21.5 MPa in 0.15 seconds.
Tensile Test of Strapping Band:68262513462000
Figure 3. SEQ Figure_3. * ARABIC 6: Tensile Test of Strapping Band0-254000
Figure 3. SEQ Figure_3. * ARABIC 7: Polypropylene Load-Displacement graph127006477000
Figure 3. SEQ Figure_3. * ARABIC 8: Polypropylene Load-Time graphThe graph in the figure 3.8 shows the behavior of PP strap band under load, and the time took it until fiber failed. It shows the high elasticity of the fiber too. The time took the fiber to fail, is around 6.35 minutes.
Figure 3. SEQ Figure_3. * ARABIC 9: Polypropylene Stress-Time graphThe graph in figure 3.9 indicates that the maximum stress applied on PP Strap Band is 13.5 MPa in 369.83 seconds.
Tests on Fresh Concrete3.4.1 Slump Test (ASTM C 143)Hang test is used to choose the value of new concrete. The hang test was finished according to ASTM C 143. It is suitable to use in the examination office and moreover at site. In spite of the way that the test is clear, yet the testing must be done purposely due to a gigantic hang may get if there is any disrupting impact all the while. The hang test will give a sensible indication of how easily a mix can be places in spite of the way that it doesn’t direct measure the work anticipated that would negligible the strong. It also determined that a hang under 25mm will demonstrate a solidified concrete and a hang that more than 125mm will exhibits a to a great degree runny bond. This hang regard varies for different structure segments. Hang test is driven on a truncated cone of steel; 12″ stature, 8″ estimation at the build, 4″ separate crosswise over in light of the best and gave handles. Estimation of hang shifts for different structures and segments as showed up in Table 3.2 after are the hang shapes that for the most part happen while doing hang of bond.
Table 3. SEQ Table_3. * ARABIC 3: Recommended slumps for various types of concrete
1.Slump test form was hose and was set on a soggy, level, non-retentive, hard surface.
2.Then by filling the form to 1/3 by volume and bar that layer with 25 uniformly separated blows.
3.After that by filling the form to 2/3 full, hits 25 quantities of hits to that layer.
4. Thus by filling the shape at the best, same 25 quantities of blows was hit.
5. In the wake of filling the shape with received methodology form was evacuated vertical way deliberately.
6. Instantly by expelling it was put topsy turvy simply close to droop cement and pole was set on a level plane on that form for estimation of droop an incentive in inches.
Allude annexure-x for the aftereffect of Slump.
Compressive Strength of ConcreteQuality of solidified cement estimated by the pressure test. The compressive quality of cement is a measure of the solid’s capacity to oppose loads which tend to pack it. The compressive quality is estimated by pounding round and hollow solid examples in pressure testing machine. The compressive quality is computed from the disappointment stack partitioned by the cross-sectional region opposing the heap and revealed in units of pound-compel per square inch (psi) or US standard units (MPa). Concrete compressive quality prerequisites canary from 2500 psi (17MPa) for private cement to 4000 psi (28MPa) and higher in business structures. Higher qualities up to and surpassing 10000 psi (70MPa) are indicated for specific applications.
Figure 3. SEQ Figure_3. * ARABIC 10: Standard concrete compressive strength graphConcrete Cylinder Compressive Test without Confinement:01358900
Figure 3. SEQ Figure_3. * ARABIC 11: Compressive strength of control specimen0-254000
Figure 3. SEQ Figure_3. * ARABIC 12: Load-Time Curve of Control Specimen014224000
Figure 3. SEQ Figure_3. * ARABIC 13: Time-Displacement Curve of Control Specimen-9525-254000Figure 3. SEQ Figure_3. * ARABIC 14: Time-Displacement Curve of Control SpecimenConcrete Cylinder Confined by Duct Tape 1-Layer08763000
Figure 3. SEQ Figure_3. * ARABIC 15: Concrete Cylinder Confined by Duct Tape 1-Layer
Figure 3. SEQ Figure_3. * ARABIC 16: Load-Time Curve of Concrete Cylinder Confined by Duct Tape in 1 Layer-1905060261500The graph in the figure 3.16 indicates, how the confined fiber influenced the concrete behavior, under load.
Figure 3. SEQ Figure_3. * ARABIC 17: Load-Displacement Curve of Concrete Cylinder Confined by Duct Tape Layer-10153987500The graph in Figure 3.17 shows that the confinement was done and both concrete and fiber took action at the same time which ultimately increased the compressive strength of concrete. After the peak load, the sudden decrease and again increase shows that the concrete sample start spalling but confining material then took the load and it shows a gradual increase
Figure 3. SEQ Figure_3. * ARABIC 18: Stress-Strain Curve of Concrete Cylinder Confined by Duct Tape 1-LayerThe figure 3.18 indicates that concrete sample confined by duct tape in 1 layer can withstand the load upto 6%.
Concrete Cylinder Confined by Duct Tape 2-Layer593199773620
Figure 3. SEQ Figure_3. * ARABIC 19027686000: Concrete Cylinder Confined by Duct Tape in 2 Layers
Figure 3. SEQ Figure_3. * ARABIC 20: Load-Time Curve of Concrete Cylinder Confined by Duct Tape in 2 LayersThe figure 3.20 indicates that, not only fiber increased the concrete compressive strength but also delayed the spalling and collapsing.
Figure 3. SEQ Figure_3. * ARABIC 21: Load-Time Curve of Concrete Cylinder Confined by Duct Tape in 2 Layers09588500
Figure 3. SEQ Figure_3. * ARABIC 22: Load-Time Curve of Concrete Cylinder Confined by Duct Tape in 2 LayersConcrete Cylinder Confined by Duct Tape 3-Layer60960035750500
Figure 3. SEQ Figure_3. * ARABIC 23: Concrete Cylinder Confined by Duct Tape Layer-304826000
Figure 3. SEQ Figure_3. * ARABIC 24: Load-Time Curve of Concrete Cylinder Confined by Duct Tape in 3-LayersThe figure 3.24 indicates the time, after failure of concrete sample. The graph shows that the confining material protect concrete sample from sudden failing and it gives some time which means it increases the concrete ductility upto some extent.
Figure 3. SEQ Figure_3. * ARABIC 25: Load-Displacement Curve of Concrete Cylinder Confined by Duct Tape in 3-Layers03746500
Figure 3. SEQ Figure_3. * ARABIC 26: Stress-Strain Curve of Concrete Cylinder Confined by Duct Tape in 3-LayersConcrete Cylinder Confined by PP Strap Band137160020129500
Figure 3. SEQ Figure_3. * ARABIC 27: Concrete Cylinder Confined by 1-Layer PP Strap Band010350500
Figure 3. SEQ Figure_3. * ARABIC 28: Load-Time Curve of Concrete Cylinder Confined by 1-Layer PP Strap BandFigure 3.28 shows the duration between concrete complete failures and spalling. It took 9.75 minutes after start spalling till the sample completely failed. PP strap band make the concrete more ductile as compared to the duct tape.
Figure 3. SEQ Figure_3. * ARABIC 29: Load-Time Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band014478000
Figure 3. SEQ Figure_3. * ARABIC 30: Stress-Strain Curve of Concrete Cylinder Confined by 1-Layer PP Strap BandConcrete Cylindrical Confined by PP Strap Band at Mid only72067129331700
Figure 3. SEQ Figure_3. * ARABIC 31: Concrete Cylinder Confined by 1-Layer PP Strap Band at Center011811000
Figure 3. SEQ Figure_3. * ARABIC 32: Load-Time Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at centerFigure 3.32 shows that the concrete sample confined by PP strap band on mid portion only gives the same compressive strength just like given by the sample confined by PP strap band on whole cylinder. The difference in these two samples is time between concrete spalling till failure. Concrete cylinder confined by 1-Layer PP strap band is become more ductile as compared to the concrete cylinder confined by the PP strap band at mid portion only.
Figure 3. SEQ Figure_3. * ARABIC 33: Load-Displacement Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at center19050825500
Figure 3. SEQ Figure_3. * ARABIC 34: Load-Displacement Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at centerConcrete Cylinder Confined by PP Strap Band on ends120510500Figure 3. SEQ Figure_3. * ARABIC 35: Concrete Cylinder Confined by 1-Layer PP Strap Band at both ends0508000
Figure 3. SEQ Figure_3. * ARABIC 36: Load-Time Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at both ends05334000
Figure 3. SEQ Figure_3. * ARABIC 37: Stress-Strain Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at both ends06858000
Figure 3. SEQ Figure_3. * ARABIC 38: Displacement-Time Curve of Concrete Cylinder Confined by 1-Layer PP Strap Band at both endsFigure 3.38 indicates the strain corresponding to the stress on vertical axis. Comparing this graph, with the one in figure 3.33 and 30.32 the time elapsed between concrete failures, and spalling is almost identical to the condition in which concrete cylinder is confined at mid. The difference between these two conditions is that, in the former case compressive strength increased more than in this case.
Concrete Ductility in Terms of TimeThe following table 3.6 shows the compressive strength comparison based on age of concrete, number of layers of confinement materials, location of wrapping material and types of confinement material with which the samples are confined. Tensile strength of the fiber play the important role in strengthening the concrete.Table 3. SEQ Table_3. * ARABIC 4: Comparison of Compressive Strength of Control Specimens with confined samplesSpecimen Peak Stress
(MPa) Peak Stress Time
(Sec) Failure Stress
(MPa) Failure Stress Time
(Sec) Ductility in terms of Time from peak Stress to Failure Stress (Sec)
Control Specimen 16.80 91.40 13.58 112.50 21.10
1-Layer Duct Tape 17.1 38.60 8.48 88 49.40
2-Layer Duct Tape 18.15 19.80 10.75 109 89.20
3-Layer Duct Tape 19.15 60.95 3.96 225 164.05
1-Layer PP Strap Band 18.49 74.55 4.97 660 585.45
1-Layer PP Strap Band at Mid 19.09 37.25 11.88 58 20.75
1-Layer PP Strap Band at ends 20.09 27.50 13.00 37 9.50
In table 3.4, the average values of 3 concrete cylinders compressive stress is given in which one is peak stress and its time and the other is Failure stress and its time. In this table the difference of time between Failure stress and Peak stress time is calculated and shows which shows the ductility of concrete.
Figure 3. SEQ Figure_3. * ARABIC 39: Time-wise elasticity of different confining materialsIn figure 3.39, numbers on the vertical axis represent time took after starting spalling of concrete till failed and the horizontal axis represents concrete samples confined by different confining material in different layers.
Figure 3. SEQ Figure_3. * ARABIC 40: Compressive strength of concreteChapter 4 DiscussionPoint by point exploratory work is clarified and introduced in past part. Aftereffects of material and kind of cement in new and solidified state are now talked about. Test outcomes show and cover the impact of age, kind of restricting material, number of layers and area of wrapping on the compressive quality. In this section a short exchange will be done and some proposal will be introduced.
Results of our experiments show that concrete cylindrical sample confined with fiber not only depends upon the fiber material by which it is confined but also depends upon the number of layers, location of wrapping material on samples i.e. entirely confined, in the middle, at both ends. The average compressive strength of control specimen after 28 days curing are 16.80 (MPa) respectively.
Average compressive strength of concrete cylindrical samples confined with 1-layer of duct tape after 28 days curing are 17.10 (MPa).
Average compressive strength of concrete cylindrical samples confined with 2-layer of duct tape after 28 days curing are 18.15 (MPa).
Average compressive strength of concrete cylindrical samples confined with 3-layer of duct tape after 28 days are 19.15 (MPa).
Average compressive strength of concrete cylindrical samples confined with 1-layer of polypropylene after 28 days are 18.49 (MPa).
Average compressive strength of concrete cylindrical samples confined with polypropylene at the midpoint of sample after 28 days are 19.09 (MPa).
Average compressive strength of concrete cylindrical sample confined with polypropylene on both ends of sample after 28 days are 20.09 (MPa).
Considering the difference between tensile strength of both fibers, logically it is expected that compressive strength of concrete confined with polypropylene would be much larger than one confined with duct tape but results are diametrically opposite in case of 1-layer of polypropylene. The reason could be either it was not confined properly or due to epoxy used. Due to the adhesive property of duct tape, it touches every single point of concrete surface. Samples confined by PP strap Band on both ends and in the middle give expectedly good result.
The most interesting result is the time elapsed after concrete start spalling to failure. Concrete samples confined with 1-layer of duct tape took around 35 seconds before start spalling. The samples confined with 2-layers of duct tape took almost 60 seconds after spalling and samples confined with 3-layer of duct tape took around 130 seconds after spalling till the samples failed.
Concrete sample confined by single layer of PP strap band, the fiber withstand the load constantly until it failed and took 9.45 minutes after the spalling starts. Concrete sample confined with PP strap band on ends only took around 25 seconds while samples confined with fiber on mid took around 56 seconds after spalling till failed.
Chapter 5Conclusion and Future RecommendationsConclusion
Following conclusions have been drawn from the examination works in this task.
The time slipped by between solid disappointment and lashing band disappointment of 1 layer was around 9.75 min. Lashing band did not expand the solid quality not surprisingly but rather it expanded the malleability of cement in vast sum which gives longer time in the wake of spalling of cement till disappointment.If confining material does not have adhesive property then it does not increase the compressive strength as much as demanded. Adhesive quality play key role in resistance of load.
Duct tape increased the strength of concrete more than polypropylene because of its softness and adhesive property. Duct tape was fully in contact with the concrete surface. If polypropylene was wrapped by some mechanical means and using some adhesive chemical to stick tightly with concrete surface then it will strengthen the concrete by a certain percentage.
Duct tape, which has low tensile strength, should be wrapped in more than one layer. Since duct tape is adhesive, multi-layers of duct tape produces more frictional force resisting compressive load.
Recommendations for FutureThe result shows that polypropylene with extraordinary high tensile strength as compared to duct tape, increased the compressive strength by small amount. The problem would be in wrapping technique and non-adhesiveness of PP strap band.
When a concrete member is to be retrofitted, special instrument for confining and high-quality epoxy should be used so that the fiber come in contact with surface of concrete entirely.
Before confining surface of concrete member should be cleaned properly. If confinement is properly done fiber will resist the load with concrete simultaneously.
Both polypropylene band and duct tape is recommended for outdoor uses due to their weather and some common chemical resistant.
In severe case aluminum sheet covering is a better option to protect it from sunlight or any chemical reaction because the aluminum is not susceptible to corrosion as it come in contact with oxygen.
If the building to be retrofitted is of high importance and more strengthening is required, the use of CFRP or GFRP is recommended.
ReferencesChai, Y.H., Priestley, M.J.N. and Seible, F. 1991. “Seismic retrofit of circular bridge columns for enhanced flexural performance”, ACI Structural Journal, Vol. 88, No. 5, pp. 572–584
Amir Mirmiran, and Mohsen Shahawy 1997. “Behavior of concrete columns confined by fiber composites”, J. Struct. Eng., 1997, 123(5): 583-590
by y. Xiao and h. Wu 2000.” Compressive behavior of concrete confined by carbon fiber composite jackets”. J. Mater. Civ. Eng., 2000, 12(2): 139-146
H. Moghaddam, S. Mohebbi & M. Samadi 2009. “Experimental and analytical investigation of concrete confined by external pre-stressed strips”, Department of Civil Engineering, Sharif University of Technology, Tehran, Iran, Rehabilitation and Retrofitting II – Alexander et al (eds)© 2009 Taylor & Francis Group, London, ISBN 978-0-415-46850-3
Scott T. Smith, M.ASCE, Seo Jin Kim and Huawen Zhang 2010. “Behavior and Effectiveness of FRP Wrap in the Confinement of Large Concrete Cylinders”, journal of composites for construction © asce / september/october 2010 / 573, J. Compos. Constr. 2010.14:573-582.
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Powanusorn, S., 2005. Effect of confinement on shear dominated reinforced concrete elements (Doctoral dissertation, Texas A&M University).
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Mirmiran, A., Shahawy, M., Samaan, M., Echary, H.E., Mastrapa, J.C. and Pico, O., 1998. Effect of column parameters on FRP-confined concrete. Journal of Composites for construction, 2(4), pp.175-185.
Samaan, M., Mirmiran, A. and Shahawy, M., 1998. Model of concrete confined by fiber composites. Journal of structural engineering, 124(9), pp.1025-1031.