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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Use of Glass Fibre Reinforced Polymer (GFRP) reinforcing bars for concrete bridge decks

Worner, Victoria Jane January 2015 (has links)
Glass Fibre Reinforced Polymer (GFRP) bars have been developed as an alternative to steel reinforcement for various structural concrete applications. Due to their non-corrossive nature, they are particularly suited for harsh environments where steel reinforcement is prone to corrosion. The purpose of this research is to determine the feasibility of GFRP reinforcing bars as concrete bridge deck reinforcement for locations, such as coastal New Zealand, where the non-corrosive benefits of GFRP may offer an alternative to traditional mild steel reinforcement. GFRP use as structural reinforcement may offer life-cycle cost benefits for certain structures as maintenance to repair corroded reinforcement is not necessary. The use of GFRP reinforcement in a New Zealand design context was investigated to directly compare the structural performance of this alternative reinforcing product. Mateen-bar, manufactured by Pultron Composites Ltd, is the GFRP reinforcing bar used in the experimental tests. Experimental investigation of tensile properties of GFRP bar samples was carried out to understand the mechanical behaviour of GFRP reinforcement and validate the manufacturer’s specifications. This series of tests highlighted the complexities of carrying out tensile testing of FRP products, due to the inability to grip the GFRP directly in a testing machine without crushing the specimen. Two phases of full-scale tests were carried out to compare the performance of bridge deck slabs reinforced with typical mild steel and GFRP reinforcing bar. This experimental testing was different to most existing research on GFRP reinforced slab performance as it did not compare the performance of a GFRP reinforcing bar area equivalent to steel, but was designed in such a way as to dependably give the same moment capacity of the steel reinforced slab design. This incorporated the recommended limit of 20% of design stress given by the manufacturer which led to an apparent over-reinforced section for the GFRP slab design. The aim of the experiments was to investigate the comparative performance of a typical New Zealand bridge deck design and a GFRP reinforced equivalent designed in such a way as is currently recommended by the manufacturer. The over-reinforcement lead to differences in conclusions drawn by other authors who have studied GFRP reinforced slab behaviour. Both flexural and concentrated loading (simulating vehicle loading) tests were carried out on both the steel and GFRP reinforced slab designs. Due to over-reinforcement the GFRP slab was considerably stiffer and stronger than the steel design, indicating that serviceability issues are unlikely to be as much of a design issue as existing literature would suggest. Deflection prediction models generally underestimate the strength of over-reinforced sections. All slabs failed in punching shear under concentrated loads, indicating that punching shear may be a critical failure mechanism for GFRP reinforced slabs Based on the findings from the extensive experimental phases, a set of design recommendations were made to further improve the potential for GFRP to be used for bridge deck design in a New Zealand context.
32

Fatigue characterisation of FRP structural tee joints

Read, Paul John Charles Lewis January 1997 (has links)
No description available.
33

Dynamic analysis of FRP laminated and sandwich plates

Meunier, Marion January 2001 (has links)
No description available.
34

New fibre-reinforced polymer box beam: investigation of static behaviour

Springolo, Mario January 2005 (has links)
This thesis discusses the development of a new type of fibre-reinforced polymer (FRP) beam for use in civil engineering systems. After a detailed evaluation of the advantages and disadvantages of current FRP beam technology, a different approach is proposed which combines traditional laminates with a novel casting technique. To pre-dimension the beam, the classical beam theory is adapted to allow for FRP materials. The resulting formulae were used to determine critical parameters, such as laminate thickness and location in the cross-section, and core dimensions, and to identify failure modes. Based on the results of this analytical study, a detailed testing program was developed. In addition to classical tests, such as bending, shear, and lateral torsion, the performance of the beam was also examined under particular loading regimes specifically designed to induce local failure modes, such as buckling of the web and bearing failure of the section under concentrated loads. The experimental results revealed very good agreement with the analytical predictions. These results were corroborated by a detailed non-linear finite-element analysis, including core cracking and laminate damage. This analysis, in particular, highlighted the synergy between bending and shear behaviour of the beam. This study has revealed that this new type of FRP beam behaves in a predictable manner. Furthermore, the experimental results verified that the cross-section, which combines traditional laminates with cast polymer concrete, did not suffer from many of the disadvantages identified in current FRP beams. The cracking of the polymer concrete under shear, however, does cause the beam to fail prior to the laminates reaching their ultimate shear stress.
35

Dynamic response of structural steel elements post-strengthened with CFRP

Kadhim, Majid January 2017 (has links)
Structural elements in buildings and civil engineering infrastructure can often be vulnerable to various kinds of impact actions during their service life. These actions could result from various sources e.g. collision of vehicles, ships and vessels or falling masses in industrial buildings. Since, for various reasons, such accidental actions have not always been considered in the existing engineering design of buildings and civil engineering structures such as bridges etc., investigation of effective structural strengthening techniques is justified. As fibre reinforced polymer (FRP) composites have commonly been employed efficiently to strengthen steel members against static and fatigue loads, examining the FRP strengthening technique to enhance structural steelwork in impact situations is the main focus of this study. The research aims to experimentally investigate the dynamic behavioural response of axially loaded steel columns and steel beams strengthened with various carbon fibre reinforced polymer (CFRP) configurations. To achieve this goal, a series of experimental tests was implemented including testing a number of CFRP strengthened and unstrengthened steel beams and columns under static and impact loads. The experimental results show that CFRP can improve the global and local behaviour of steel members subjected to impact loads. This improvement varied depending on the CFRP configuration, the amount of CFRP and the pre-existing axial load value in the member. In order to examine all the parameters that can affect the dynamic behaviour of CFRP strengthened steel members in addition to those not included in the experimental programme, a comprehensive numerical simulation of the experimental work was carried out using a validated finite element model. Afterwards, an extensive parametric study was conducted to provide a comprehensive understanding of the behaviour of CFRP strengthened steel members subjected to impact load. The simulation results illustrate that the effectiveness of CFRP increases with high impact energies. The parametric study results have also revealed that the configurations and distributions of CFRP have a major influence on the effectiveness of the reinforcement. A detailed numerical assessment has also been performed to find the CFRP effectiveness when applied to full-scale steel columns. It has been found that strengthening with CFRP in practical quantities and configurations could prevent steel columns from failure under transverse impact loading. The strengthening effectiveness was found to be dependent on boundary conditions, impact velocity, impact mass, impact location, preloading level, impact direction, CFRP configuration, and the length and thickness of the CFRP. Based on the results obtained from the full-scale simulation, it has been found that the CFRP strengthening technique can be used efficiently and effectively at the scale of elements common in everyday building and infrastructure. This study also provides a useful database for different kinds of strengthening configurations, impact velocities and masses, boundary conditions, etc.
36

The effect of debonding in fibre-reinforced composites on ultrasonic backscattering

Beattie, P. January 1992 (has links)
The work presented in this thesis concerns the problem of detecting and characterising the effect of fibre-matrix debonds in a fibre-reinforced composite, on ultrasonic backscattering. Theoretical and experimental investigations were conducted into this problem. Three mathematical models were examined. The first assumed that the debond was a thin crack with non-contacting faces surrounding the fibre. The second modelled the debond by allowing tangential slip between the matrix and fibre defined by an effective shear modulus, K. For the third model, the debond was approximated by a thin visco-elastic layer separating the matrix and fibre. The results of the modelling suggested that for an incident longitudinal wave, the first model acts as an air-filled void with a sharp resonance present in the low ka region. The second and third models both show the backscattering to be attenuated. Experimental investigations were carried out on scale models of a single fibre embedded in an araldite matrix. Steel or copper wires were used for the reinforcing fibre. The agreement between theory and experiment for a well-bonded wire was excellent. The effect on the longitudinal backscattered wave of the wire immediately after debonding was to attenuate heavily the resonances in the backscatter form function. However, after approximately an hour the scatter is seen to relax, closely resembling that from a well-bonded wire. In view of the only partial ability of longitudinal incident waves to detect debonds, shear wave (SH) incidence was investigated. It was shown that shear waves were far more sensitive to the presence of fibre-matrix debonds.
37

Stability analysis of P.F.R.P. box-sections

Javed, Muhammad Afzal January 2003 (has links)
lass fibre reinforced plastic (GRP) structural profiles, in standard shapes and sizes are now being commercially manufactured by the process of pultrusion. GRP profiles are light weight, posses higher specific strengths and are more durable than the conventional metal or concrete counterparts. GRP pultruded profiles have open or closed cross-sections comprising thin composite walls of low elastic moduli. Stability failure has been identified as the main cause of failure for these profiles when subjected to compressive stresses, as it may occurs at stresses much lower than the ultimate strengths. Therefore, the load carrying capacities of composite compression members mainly depends upon stability criteria. The conventional stability analyses for the prediction of buckling loads are not considered adequate as the GRP material is orthotropic and its behaviour is different from steel (non-yielding). The existing guidance for the design of composite members under compression ignores the presence of geometrical imperfections inherited in the pultruded profiles, whilst, experimental evidence suggests considerable loss of stiffness due to the imperfections particularly in the intermediate column heights. The design guidance provided by the manufacturers gives empirical equations based on data obtained from experiments on specified profiles. A universal design curve based on the experimental results of concentrically loaded GRP columns has been developed and presented. However, conducting a vast experimental study is not always feasible. The need to develop a procedure, predicting failure load numerically for the development of a design curve for GRP columns has been recognised. Two GRP box-sections (closed square cross-sections) have been investigated for failure/buckling loads using experimental and numerical methods. In the experimental phase, specimen columns of various heights have been concentrically loaded in compression to measure the failure loads. Experimental results have been compared with the theoretical predictions made using classical methods and the equations given by the design manuals. Based on the experimental and analytical failure loads, an experimental design curve has been derived. In the numerical study, 3-dimensional full scale finite element models representing experimental configuration of the composite columns, have been analysed using both linear and nonlinear solutions. Imperfections of known amplitudes have been included parametrically to establish the sensitivity of the failure loads towards imperfections. Imperfect model have been calibrated for the estimation of imperfection amplitude present in the profiles using experimental data. Using the numerical and analytical data, a design curve has been derived establishing interaction coefficients for each profile. The numerical design curve is compared with the experimental design curve for the validation of the numerical procedure adopted in this study. Effects of perforations (circular holes) on the buckling stiffness of GRP box-section columns have also been investigated. Holes are drilled in the walls of profiles and tested experimentally to measure the loss in the buckling loads. Finite element models of columns with holes have been developed and analysed for buckling loads. Comparisons of experimental and numerical results are plotted. For use in the numerical representation of the composite columns, mechanical properties of the orthotropic GRP material of the both sections have been established analytically and experimentally. In-plane shear properties have been measured by physically testing standard sized coupons, extracted along the length of profiles. However, short coupons were available in the transverse directions due to dimensional constraints. Short coupons, similar in geometry to the standard coupon, but smaller in size, have been validated for performance using finite element analyses and comparing the outcomes with the models of standard coupons. Both standard and short coupons have been used for the experimental measurement of the in-plane shear properties. Compression properties have also been measured experimentally. Ultimate failure/buckling loads of the composite columns depend upon their heights, material properties, and the cross-sectional dimensions. These factors have been combined into one characteristic parameter 'λ', the slenderness ratio. As the later two factors are constant for a particular box-section profile, the ultimate loads depend upon column heights. Four types of failure modes; global, local, modal interaction and material failure have been observed. The loss in the buckling stiffness is minimal for smaller circular holes, provided the interval between holes is not less than 20 times the diameter of the holes. For bigger holes and an inter hole spacing of 10time the diameter, a loss of 30% have been measured. Finite element representation of pultruded columns adequately predicted the numerical failure loads and failure modes for most of the column heights.
38

Structural enhancements with fibre-reinforced epoxy intumescent coatings

Triantafyllidis, Zafeirios January 2017 (has links)
Epoxy intumescent coatings are fire protection systems for steel structural elements that are widely used in applications that protection from severe hydrocarbon fires is required, such as oil and gas facilities. These polymer coatings react upon heating and expand into a thick porous char layer that insulates the protected steel element. In the typical fire scenarios for these applications, the intumescent coatings must resist very high heat fluxes and highly erosive forces from ignited pressurised gases. Hence, continuous fibre reinforcement is embedded in the thick epoxy coating during installation, so as to ensure the integrity of the weak intumesced char during fire exposure. This reinforcement is typically in the form of a bidirectional carbon and/or glass fibre mesh, thus under normal service conditions a fibre-reinforced intumescent coating (FRIC) is essentially a lightly fibre-reinforced polymer (FRP) composite material. This thesis examines the impacts of embedded high strength fibres on the tensile behaviour of epoxy intumescent materials in their unreacted state prior to fire exposure, and the potential enhancements that arise in the structural performance of elements protected with FRICs. An experimental programme is presented comprising tensile coupon tests of unreacted intumescent epoxies, reinforced with different fibre meshes at various fibre volume fractions. It is demonstrated that the tensile properties of FRICs can be enhanced considerably by including increasing amounts of carbon fibre reinforcement aligned in the principal loading direction, which can be tailored in the desired orientation on the coated structural members to enhance their load carrying capacity and/or deformability. An experimental study is presented on coated intact and artificially damaged I-beams (simulating steel losses from corrosion) tested in bending, demonstrating that FRICs can enhance the flexural response of the beams after yielding of steel, until the tensile rupture of the coatings. An analytical procedure for predicting the flexural behaviour of the coated beams is discussed and validated against the obtained test results, whereas a parametric analysis is performed based on this analytical model to assess the effect of various parameters on the strengthening efficiency of FRICs. The results of this analysis demonstrate that it is feasible to increase the flexural load capacity of thin sections considerably utilising the flexural strength gains from FRICs. Finally, a novel application is proposed in this thesis for FRICs as a potential system for structural strengthening or retrofitting reinforced concrete and concrete-encased steel columns by lateral confinement. An experimental study is presented on the axial compressive behaviour of short, plain concrete and concrete-encased structural steel columns that are wrapped in the hoop direction with FRICs. The results clearly show that epoxy intumescent coatings reinforced with a carbon fibre mesh of suitable weight can provide lateral confinement to the concrete core resisting its lateral dilation, thus resulting in considerable enhancements of the axial strength and deformability of concrete. The observed strengthening performance of the composite protective coatings is found to be at least as good as that of FRP wraps consisting of the same fibre reinforcement mesh and a conventional, non-intumescent epoxy resin. The predictive ability of existing design-oriented FRP confinement models is compared against the experimental results, and is found to be reasonably precise in predicting the peak strength of the tested columns, hence existing models appear to be suitable for design and analysis of column strengthening schemes with the proposed novel FRIC system. The research presented herein shows clearly that FRICs have a strong potential as alternative systems for consideration in the field of structural strengthening and rehabilitation, since they can provide substantial enhancements in the load carrying capacity for both applications considered. At the same time FRICs can thermally protect the underlying structural elements in the event of a fire, by intumescing and charring, thus potentially eliminating the need for additional passive fire protection that is common with conventional fire-rated FRP wrapping systems. Although this thesis provides a proof-of-concept for use of the proposed novel FRICs as structural strengthening materials, considerable additional research is particularly required to study their fire protection performance when applied to concrete substrates, to make use of the proposed hybrid functionality with confidence.
39

Tensile creep of cracked macro synthetic fibre reinforced concrete

Babafemi, Adewumi John 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Macro synthetic fibres are known to significantly improve the toughness and energy absorption capacity of conventional concrete in the short term. However, since macro synthetic fibre are flexible and have relatively low modulus of elastic compared to steel fibres, it is uncertain if the improved toughness and energy absorption could be sustained over a long time, particularly under sustained tensile loadings. The main goal of this study is to investigate the time-dependent crack mouth opening response of macro synthetic fibre reinforced concrete (FRC) under sustained uniaxial tensile loadings, and to simulate the flexural creep behaviour. For the purpose of simulating the in-service time-dependent condition, all specimens were pre-cracked. Experimental investigations were carried out at three levels (macro, single fibre and structural) to investigate the time-dependent behaviour and the mechanisms causing it. At the macro level, compressive strength, uniaxial tensile strength and uniaxial tensile creep test at 30 % to 70 % stress levels of the average residual tensile strength were performed. To understand the mechanism causing the time-dependent response, fibre tensile test, single fibre pullout rate test, time-dependent fibre pullout test and fibre creep test were done. Flexural test and flexural creep test were done to simulate the structural level performance. The results of this investigation have shown significant drop in stress and increase in crack width of uniaxial tensile specimens after the first crack. The post cracking response has shown significant toughness and energy absorption capacity. Under sustained load at different stress levels, significant crack opening has been recorded for a period of 8 month even at a low stress level of 30 %. Creep fracture of specimens occurred at 60 % and 70 % indicating that these stress levels are not sustainable for cracked macro synthetic FRC. The single fibre level investigations have revealed two mechanisms responsible for the time-dependent crack widening of cracked macro synthetic FRC under sustained loading: time-dependent fibre pullout and fibre creep. In all cases of investigation, fibre failure was by complete pullout without rupture. Flexural creep results have shown that the crack opening increases over time. After 8 months of investigation, the total crack opening was 0.2 mm and 0.5 mm at 30 % and 50 % stress levels respectively. Since the crack opening of tensile creep and flexural creep specimens cannot be compared due to differences in geometry, specimen size, load transfer mechanisms and stress distribution in the cracked plane, a finite element analysis (FEA) was conducted. Material model parameters obtained from the uniaxial tensile test and viscoelastic parameters from curve fitting to experimental uniaxial creep results have been implemented to successfully predict the time-dependent crack opening of specimens subjected to sustained flexural loading. Analyses results correspond well with experimental result at both 30 % and 50 % stress levels. / AFRIKAANSE OPSOMMING: Makro sintetiese vesels is bekend daarvoor dat dit die taaiheid en energie absorpsie van konvensionele beton beduidend verbeter in die kort termyn. Aangesien makro sintetiese vesels buigsaam is met 'n relatiewe lae styfheidsmodulus in vergeleke met staalvesels, is dit onseker of die verhoogde kapasiteit vir energie absorpsie en taaiheid volgehou kan word oor die langer termyn, veral in gevalle waar dit aan volgehoue trekkragte blootgestel is. Die hoofdoel van die studie is om die tydafhanklike-kraakvergrotingsgedrag van makro sintetiese veselversterkte beton (VVB) wat blootgestel is aan volgehoue trekkragte te ondersoek asook die simulasie van die kruipgedrag in buig. Ten einde die werklike toetstande te simuleer is al die proefstukke doelbewus gekraak in 'n beheerde manier voor die aanvang van die toetse. Die eksperimentele ondersoek is uitgevoer op drie vlakke (makro, enkelvesel en strukturele) om die tydafhanklike gedrag sowel as die meganismes verantwoordelik vir hierdie gedrag te ondersoek. Op die makro-vlak is druktoetse gedoen saam met eenassige trek- en eenassige kruiptoetse met belastings tussen 30 % en 70 % van die gemiddelde residuele treksterkte. Om die meganisme wat die tydafhanklike gedrag veroorsaak te verstaan is veseltoetse, enkel vesel uittrektoetse, enkel vesel uittrek kruiptoetse asook kruiptoetse op vesels gedoen. Buigtoetse en buig kruiptoetse is ook gedoen om die gedrag op die strukturele vlak te ondersoek. Die resultate van hierdie ondersoek wys dat daar 'n beduidende val in spanning is en dat daar gepaardgaande kraak opening in die eenassige trek proefstukke plaasgevind het na die vorming van 'n kraak. Die na-kraak gedrag wys beduidende taaiheid en energie absorpsie kapasiteit. Gedurende die volgehoue trekbelasting by verskillende spanningsvlakke is beduidende kraakvergroting opgemerk, selfs by 30 % belasting na 8 maande. Kruipfaling het plaasgevind by proefstukke met belastings van 60 % en 70 % wat daarop wys dat hierdie spanningsvlakke nie geskik is vir gekraakte makro sintetiese VVB nie. Op die enkel veselvlak is twee meganismes geïdentifiseer wat verantwoordelik is vir die kraakvergroting oor tyd vir gekraakte makro sintetiese VVB met volgehoue trekbelasting: tydafhanklike vesel uittrek en vesel-kruip. In alle gevalle in hierdie ondersoek was die falingsmeganisme vesels wat uittrek. Buig kruiptoets resultate wys dat die krake vergroot oor tyd. Na 8 maande van ondersoek was die kraakwydtes 0.2 mm en 0.5 mm by 30 % en 50 % spanningsvlakke onderskeidelik. Aangesien die kraak opening van eenassige trek kruiptoetse en die buig kruiptoetse nie direk met mekaar vergelyk kan word nie weens die verskille in geometrie, proefstuk grootte en spanningsverdeling in die kraakvlak, is 'n eindige element analises (EEA) gedoen. Materiaal eienskappe is bepaal deur gebruik te maak van die eenassige kruip trektoets se resultate en viskoelastiese parameters is bepaal deur middel van kurwepassing van die resultate. Dit was gebruik om suksesvol die buig kruip kraak opening gedrag te simuleer. Die analises se resultate vergelyk goed met die eksperimentele data by beide 30 % en 50 % spanningsvlakke.
40

Establishment of performance-based specifications for the structural use of locally available macro-synthetic fibres

Odendaal, Courtney Megan 03 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: FRC (Fibre-reinforced concrete) has become a common form of secondary and even primary reinforcing in some applications throughout the world. In South Africa, the structural applications are limited primarily to steel fibres while cheaper, lighter and more durable synthetic fibres have been side-lined due to low stiffnesses. The purpose of this research project is to investigate the behaviour of synthetic fibre-reinforced concrete (SynFRC) using fibres which are locally available in South Africa, and to propose a performance-based specification and test method for the use of these fibres. In order to achieve this, single fibre pull-out tests were performed on four locally available polypropylene fibres. It was found that the average bond stresses of the fibres are influenced primarily by the fibre cross sectional shape, longitudinal geometry and surface treatment, and secondarily by the aspect ratio. The W/C ratio had little effect on the single fibre performance of non-treated fibres, but appeared to have a slight effect on the single fibre performance of the surface treated fibre. From the experimental results, the highest fibre bond stress will be generated by using a fibre with an X-shaped cross section, longitudinal crimping and applying a surface treatment to this fibre. It also appears that the bond stress distribution for flat fibres is close to uniform, while the bond stress distribution for non-flat crimped fibres has a high mechanical interlock component at the surface end. Macro-mechanical performance tests were performed by means of the BS EN 14651 (2007) three point beam bending test and the ASTM C1550 (2012) Round Determinate Panel Test (RDPT). These tests were selected following a thorough literature review. The RDPT was found to be more consistent and able to identify trends which the three point beam bending test could not. In addition, the three point beam bending test’s most popular output, the Re,3 value tended to be misleading with varying W/C ratios, and it is recommended that the equivalent flexural tensile strength be used instead if the three point beam bending test is used. The macro-mechanical testing showed that increasing the fibre dosage did increase post-cracking performance. The flat fibres’ performance was significantly better than that of the non-flat fibres, and also increased at a faster rate with increasing fibre dosage. The post-cracking performance decreased with increasing W/C ratios and increasing aggregate sizes. The macro-mechanical performance was inversely proportionate to the single fibre performance. The macro-mechanical performance decreased with increasing fibre bond stress, and increased with increasing equivalent diameter, which equates to fewer fibres in a set volume of fibres. Finally, basic principles were developed from the data. These principles were used to predict the RDPT and three point beam bending test performance parameters based on fibre dosage, single fibre properties (bond stress and equivalent diameter), W/C ratio and aggregate size from the available data. The principles can be further refined with more experimental data. / AFRIKAANSE OPSOMMING: Vesel-gewapende beton word regoor die wêreld as ’n algemene vorm van sekondêre en selfs primêre versterking gebruik. In Suid-Afrika is die strukturele toepassings hoofsaaklik tot staal vesels beperk, terwyl goedkoper, ligter en meer duursame sintetiese vesels vermy word as gevolg van lae styfhede. Die doel van hierdie navorsingsprojek is om die gedrag van sintetiese-veselversterktebeton (SynFRC) te ondersoek deur gebruik te maak van vesels wat in Suid-Afrika beskikbaar is, en 'n prestasie-gebaseerdespesifikasie en toetsmetode vir die gebruik van sintetiese vesels voor te stel. Enkelveseluittrektoetse is op vier plaaslik beskikbare polipropileen vesels uitgevoer. Daar is gevind dat die gemiddelde verbandspanning van die vesel hoofsaaklik deur die vesel deursnee vorm, lengte meetkunde en oppervlak behandeling beïnvloed word, en tweedens deur die aspek verhouding beïnvloed. Die W/C-verhouding het min effek op die enkelveselprestasie van nie-behandelde vesels, maar het 'n effek op die enkeleveselprestasie van die oppervlak-behandelde vesel gehad. Die eksperimentele resultate wys dat die hoogste vesel verbandspanning deur 'n vesel met 'n X-vormige deursnit, lengte krimping en toepassing van 'n oppervlak behandeling gegenereer sal word. Dit blyk ook dat die verbandspanningverspreiding vir ’n plat vesel naby aan uniform is, terwyl die verbandspanningverspreiding vir ’n nie-plat gekrimpde vesel 'n hoë meganiese grendeling komponent op die oppervlak ente het. Makro-meganiese prestasietoetse is uitgevoer deur middel van die BS EN 14651 (2007) driepuntbalkbuigtoets en die ASTM C1550 (2012) RDPT. Hierdie toetse is ná ’n deeglike literatuuroorsig gekies. Die RDPT is meer konsekwent en is in staat om neigings te identifiseer wat die driepuntbalkbuigingtoets nie kan nie. Daarbenewens, met wisselende W/C verhoudings, is die driepuntbalkbuigtoets se gewildste resultaat, die Re,3-waarde geneig om misleidend te wees. Dit word aanbeveel dat die ekwivalentebuigtreksterkte in plaas van die Re,3-waarde as die drie punt balk buig toets resultaat gebruik word. Die makro-meganiesetoets het getoon dat die verhoging van die veseldosis ’n toename in na-krakingprestasie veroorsaak. Die plat vesels se prestasie was aansienlik beter as die van nie-plat vesels, en het met 'n toenemende veseldosis teen 'n vinniger koers verhoog. Die na-krakingprestasie het met toenemende W/C en die verhoging van die klip grootte afgeneem. Die makro-meganieseprestasie was omgekeerd eweredig aan die enkelveselprestasie. Die makro-meganieseprestasie het met toenemende vesel band stres verminder, en het met 'n toenemende gelykstaande deursnee (wat gelykstaande is aan minder vesel in 'n stel volume van vesel) vergroot. Ten slotte is basiese beginsels uit die data ontwikkel. Hierdie beginsels is gebruik om die RDPT en driepuntbalkbuigtoets prestasieparameters gebaseer op veseldosis, enkelveseleienskappe (verbandspanning en ekwivalentediameter), W/C-verhouding en klip grootte van die beskikbare data te voorspel. Die beginsels kan met meer eksperimentele data verder verfyn word.

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