Addition Of Polypropylene Fibers Research Articles

Behaviour of Hybrid Fibre-Reinforced Ternary Blend Geopolymer Concrete Beam-Column Joints under Reverse Cyclic Loading.

Beam–column joints are extremely vulnerable to lateral and vertical loads in reinforced concrete (RC) structures. This insufficiency in joint performance can lead to the failure of the whole structure in the event of unforeseen seismic and wind loads. This experimental work was conducted to study the behaviour of ternary blend geopolymer concrete (TGPC) beam-column joints with the addition of hybrid fibres, viz., steel and polypropylene fibres, under reverse cyclic loads. Nine RC beam-column joints were prepared and tested under reverse cyclic loading to recreate the conditions during an earthquake. M55 grade TGPC was designed and used in this present study. The primary parameters studied in this experimental investigation were the volume fractions of steel fibres (0.5% and 1.0%) and polypropylene fibres, viz., 0.1 to 0.25%, with an increment of 0.05%. In this study, the properties of hybrid fibre-reinforced ternary blend geopolymer concrete (HTGPC) beam-column joints, such as their ductility, energy absorption capacity, initial crack load and peak load carrying capacity, were investigated. The test results imply that the hybridisation of fibres effectively enhances the joint performance of TGPC. Also, an effort was made to compare the shear strength of HTGPC beam-column connections with existing equations from the literature. As the available models did not match the actual test results, a method was performed to obtain the shear strength of HTGPC beam-column connections. The developed equation was found to compare convincingly with the experimental test results.

Experimental Analysis for Performance of Concrete with Addition of Steel Fibres, SBR and Polypropylene Fibres

Sufficient experimentation is observed in literature to examine the brittle behaviour of concrete. Presently, addition of different modified polymer and fibres can be treated as an effective way for improving the behaviour of concrete. Steel fibres are now generally mixed with concrete as because of such fibres sufficient strengths are gained. Fibre Reinforced Concrete acquires high stiffness, strength and durability subjected to different environment. In this experimental investigation it is mixed steel fibres with concrete with various percentages (0.35% to 0.85%) with addition of Polypropylene fibre. The primary objective is first to check whether the employment of steel fibres allows the improvement in strength. Next objective is to verify the effect of a mixing of steel fibres and modified polymer namely SBR. The third objective of the present study deals with the combination of steel fibres with synthetic polypropylene fibres in varying percentages. Preparation of specimen is performed in lab for different contents% of styrene butadiene rubber polymer with the hooked end SF. The experimental program includes cube, cylinder and beam specimens with fabricated in 1% to 10% steel fibres. Further 15% modified polymer-SBR is added in the different mixes. After this 0.15% to 0.25% polypropylene is mixed to M30 and M40 grade of concrete. The volume fraction for fibre having 100 kg/m3 of steel fibres (1.27% Vf) may be effectively employed. It is seen that by varying the %contents of SF’s and SBR; strong bond is developed leading to bridge of micro cracks by the polypropylene in RC members.

Experimental investigation on dynamic mechanical properties of sandy clay treated with alkali-activated metakaolin cement and discrete polypropylene fibers

The dynamic mechanical properties and dynamic energy absorption capacity of marine sandy clay, which was stabilized by cement with partial substitution of alkali-activated metakaolin (AAMK) and discrete polypropylene fibers, were experimentally investigated at strain rates of 80–280 s−1. The AAMK, as partial replacement of cement, is eco-friendly and economical, and polypropylene fibers with corrosion resistance can withstand severe environmental conditions. Dynamic mechanical properties of 16 different mix ratios were experimentally examined via split Hopkinson compression pressure bar (SHPB) tests. Typical macroscopic post-impact fragment patterns I and II were observed in dynamic stress–strain curves and macroscopic fragmentations. The results confirmed an obvious enhancement in the dynamic compressive strength and energy absorption density due to the use of cement with partial substitution of AAMK and the addition of polypropylene fibers and sand. Based on scanning electron microscopy (SEM) tests and nuclear magnetic resonance (NMR) tests, cemented sandy clay specimens treated with 0.2% fiber contents or higher exhibited a denser network of soil particles with hydration products. The connection mechanism and typical interface between fiber-sand-hydrate-sandy clay particles were observed via SEM tests. Furthermore, an optimal mix ratio was proposed to satisfy the demands of high dynamic mechanical properties, energy absorption capacity, and economic and environmental constraints. The optimal mix ratio corresponded to 0.2% fiber content or higher and sand content of up to 16%. Additionally, it was observed that the dynamic compressive strength of samples with 0.1% fibers or less deteriorated. Based on absorption energy density and failure modes analysis, the fiber content should be higher than or equal to 0.2% to effectively reduce the degree of fragmentation and increase the size of fragments.

Experimental Evaluation of Carbon Reinforced TRC with Cement Suspension Matrix at Elevated Temperature.

Textile-reinforced concrete (TRC) is a new composite material comprising high-performance concrete and textile reinforcement from textile yarns with a matrix, usually consisting of epoxy resins (ER). The most significant advantage of ER is the homogenization of all filaments in the yarn and full utilization of its tensile potential. Nevertheless, ER matrix is a critical part of TRC design from the perspective of the fire resistance due to its relatively low resistance at temperatures of approximately 120 °C. This work expands the previously performed mechanical tests at normal temperatures with cement suspension (CS) as a non-combustible material for the yarn matrix. Here, the mechanical properties of CS matrix at elevated temperatures were verified. It was found that the addition of polypropylene fibers into HPC negatively affected the mechanical results of CS matrix specimens. Simultaneously, thermal insulation effect of the covering layers with different thicknesses did not significantly influence the residual bending strength of specimens with CS matrix and achieved similar results as reference specimens. Furthermore, all specimens with ER matrix progressively collapsed. Finally, CS as a textile reinforcement of yarn matrix appears to be a suitable solution for increasing the temperature resistance of TRC structures and for substituting synthetic resins.

The Triaxial Test of Polypropylene Fiber Reinforced Fly Ash Soil.

Recently, soil reinforcement using arranged or randomly distributed fibers has attracted increasing attention in geotechnical engineering. In this study, polypropylene (PP) fibers with three lengths (6, 12, and 24 mm) and three mass percentages (0.5%, 1%, and 1.5%) were used to reinforce a coal fly ash soil (FAS) mixture. Unconsolidated, undrained triaxial tests were carried out in order to study the mechanical properties of the polypropylene fiber-reinforced FAS mixture and evaluate the impact of fiber on the shear strength of the FAS mixture. It is found that the fiber length of 12 mm could significantly improve the shear strength of the polypropylene fiber reinforced FAS mixture, and little effect is shown on the shear strength while using a fiber length of 24 mm. Additional fibers enhance the energy absorption capacity of the FAS specimens and therefore the highest energy absorption capacity occurs when the fiber content is 1% and the fiber length is 12 mm. The peak deviator stress enhances impressively with the addition of polypropylene fiber. The impact of fiber on the peak deviator stress is the largest when fiber content is within 1.0%. The fiber length has little effect on the peak deviator stress when it exceeds 12 mm.

Interfacial bond characteristics of polypropylene fiber in steel/polypropylene blended fiber reinforced cementitious composite

This paper investigates for the first time the interfacial bond characteristics of polypropylene fiber in blended hybrid steel-polypropylene fiber reinforced concrete, which contributes to improving the polypropylene fiber utilization efficiency and then promoting the overall performance of the composite. Single-sided fiber pullout tests were performed on 21 groups of macro polypropylene fiber pullout specimens. The complete fiber pullout load-slip responses were captured, and the fiber interfacial properties were analyzed for different hybrid fiber dosage, fiber embedded length and matrix length. Results show that partial fiber rupture with a non-zero residual pullout load is the dominant failure mode. Increasingly severe abrasion at the PF surface is observed during the pullout process, resulting in a strain hardening behavior after a bent-over point is reached in a typical pullout load-slip curve. An appropriate polypropylene fiber addition in the concrete matrix can effectively improve the maximum pullout load, residual pullout load, the pullout energy, and the contribution of polypropylene fibers is more critical than that of steel fibers. Besides, the reinforcement of polypropylene fibers on the toughness and cracks resistance is proven to be more pronounced in plain concrete than that in high-strength concrete. Finally, theoretical analyses were performed on the polypropylene fiber direct pullout problem and the frictional bond stress vs. slippage relation is obtained with hybrid fiber content taken into account. The research provides a base for an optimized hybrid fiber reinforced concrete with high fiber efficiency and less cement consumption.

Shrinkage behavior and mechanical properties of alkali activated mortar incorporating nanomaterials and polypropylene fiber

Blended ground granulated blast slag (GGBS), low-calcium fly ash (FA), nano silica (NS), and nano alumina (NA) with/without polypropylene fiber (PPF) had a significant effect on the development length of alkali activated mortar (AAM) cured at various humidity levels and curing ages. This paper presents the behavior of alkali activated mortar with 50% FA and 50% GGBFS binder materials and the alkali ratio of sodium silicate to sodium hydroxide (SS/SH) is 2.5. The molar concentration of sodium hydroxide (NaOH) used was 12 M. Feasibility Comparisons between the different humidity 60%–98% of at 23 ± 3 C° were examined. The strength behavior of alkali-activated mortar with different curing ages was also evaluated. Scanning electron microscopy (SEM) analysis and X-ray diffractions (XRD) were also conducted to clarify the effect of nanomaterials and PPF on the microstructures of AAM. It was found that the shrinkage values of AAM were decreased with the addition of polypropylene fiber and nanomaterials. The combined use of both nanomaterials had better performance than the use of nano SiO2 and/or nano Al2O3 alone. The combined use of PPF with nanomaterials had a superior reduction in shrinkage and expansion and increment on strength values; the minimum shrinkage, expansion values, and maximum strength were found at AAM mix incorporating 2%NS-1%NA-0.5%PPF. The SEM analysis and XRD evaluation indicates the significant effect of nanomaterials on the microstructures and bond strength of AAM. The microstructure of the mixes incorporating both nanomaterials and PPF was denser than other mixes without nanomaterials and/or PPF and showed lower micro cracks.

An Investigation into Properties of Concrete by Partial Replacement of Sand with Wheat Straw Ash and Addition of Polypropylene Fiber

Concrete is the more widely utilized construction material on the planet earth, particularly in evolving and developing nations. Concrete was created as a stronger and more resistant building material as it was worked upon over time. Gradually, the man figured out how to create it, transport it, and utilize it more efficiently. We know that concrete is made from cement, sand, aggregate, and water. Out of these, some of them may be replaced with some other material like wheat straw ash, rice husk ash, fly ash, etc. for various purposes, mostly to utilize waste material without affecting the important properties of concrete beyond acceptable limits. This study deals with an investigation into the properties of concrete by partial replacement of sand with wheat straw ash and the addition of polypropylene fiber in it. Wheat Straw is the portion of leftovers of the wheat crop after it is harvested. In most countries, it is a waste. People burn it and cause pollution and health hazards, good strength and high performance in concrete are very much required in future construction work. It is felt that fiber dispersion in concrete is one method to improve the structural characteristics of concrete.

Green Building Design Concept: A Sustainable Approach

Concrete is the more widely utilized construction material on the planet earth, particularly in evolving and developing nations. Concrete was created as a stronger and more resistant building material as it was worked upon over time. Gradually, the man figured out how to create it, transport it, and utilize it more efficiently. We know that concrete is made from cement, sand, aggregate, and water. Out of these, some of them may be replaced with some other material like wheat straw ash, rice husk ash, fly ash, etc. for various purposes, mostly to utilize waste material without affecting the important properties of concrete beyond acceptable limits. This study deals with an investigation into the properties of concrete by partial replacement of sand with wheat straw ash and the addition of polypropylene fiber in it. Wheat Straw is the portion of leftovers of the wheat crop after it is harvested. In most countries, it is a waste. People burn it and cause pollution and health hazards, good strength and high performance in concrete are very much required in future construction work. It is felt that fiber dispersion in concrete is one method to improve the structural characteristics of concrete.

Mechanical behaviour of sandy soils embankments treated with cement and reinforced with discrete elements (fibres)

It is well known that the reinforcement of the Soil is considered as a solution to its stability problems. This technique ameliorates the mechanical and physical comportment of the soil. Based on this, this research paper aims at investigating the behaviour of a specific type of dried-cemented-sandy soil reinforced with discrete elements such as polypropylene fiber basically through experimental tests. The latter are a series of consolidated drained triaxial tests which were carried out on samples of sand that are prepared with 0, 3 and 6% of cement, reinforced with 1% of polypropylene fiber (12, 18 mm) randomly distributed. Furthermore, those contents are measured by the volume of dry sand. In addition to these tests, a parametric study has also been conducted on a road embankment using a finite element program such as Plaxis 2D in order to observe the variation of different parameters like safety factor and the displacements (Ut, Ux, Uy). The test results showed that the addition of cement and polypropylene fiber of different accommodations increased both cohesion and friction angle of sands while the numerical results indicated that the presence of these additions improved the safety factor and decreased significantly the displacements.

Effect of expanded polystyrene beads on the properties of foam concrete containing polypropylene fiber

In this study, foam concrete was produced using 3 different volumes of EPS beads (up to 100%), 3 different volumes of polypropylene(PP) fiber (up to 0.1)%, sand and 40% pre-produced foam which is fixed by volume. The water-cement ratio was 0.4 and the sand-cement ratio was chosen as 1. The foam concrete were cast into molds with a size of 100 x 100 x 500 mm and 150 x 150 x 150 mm prism. Unit weight, ultrasonic pulse, water absorption, splitting tensile strength, bending strength and compressive strength tests were achieved. Foam concrete were kept in laboratory standard conditions. According to the results of study, unit weight and ultrasonic pulse velocity vary between 970-1350 kg/m3 and 1.6-2.6 km/sec, respectively. The water absorption of the foam concrete decreased up to 65% as the EPS beads ratio increased. Since EPS beads do not contribute to the strength and act like a void, splitting tensile strength in specimens containing EPS beads decreased by up to 70%. The use of fiber contributes to the splitting tensile strength, especially in specimens that do not contain EPS beads, and it increased the strength by 78%. Similarly, the flexural strength of the PP fiber addition increased by up to 70%. As the EPS beads ratio increased, the flexural strengths decreased by 77%. With the addition of PP fiber, the compressive strength increased by 55%. However, since EPS beads' strength is negligible, it caused a 60% decrease in compressive strength.

Strength, Elastic Properties and Fiber-Matrix Interaction Mechanism in Geopolymer Composites.

The current geopolymers have limited mechanical strength against the effect of tension, which makes them susceptible to brittle failure. However, owing to their potential as a sustainable construction material, there is growing interest in improving the poor mechanical properties of geopolymers. This study experimentally investigated crucial properties of polypropylene-fiber-reinforced fly ash-based geopolymer composites. The effects of polypropylene fibers (PPF) addition (0.5%, 1.0% and 1.5% by volume) on the mechanical properties of the geopolymer composites were investigated with respect to compressive and flexural strength, deformation behavior of Young’s and shear moduli, and resilience capacity. In addition, scanning electron microscopy was performed to establish the morphology of the geopolymeric matrix and the fiber–matrix interfacial interaction. The addition of PPF significantly increased the flexural strength: compared with the control, at 7 days it was 27% greater for the 0.5% PPF composite and 65% greater for the 1.0% PPF composite. By 14 days it was 31% and 61% greater, respectively. By contrast, the 1.5% PPF composite had lower strength parameters compared with the control because the fiber dispersion increased the porosity. Similar trends were seen for resilience. The SEM observations showed the dispersion of the fibers and helped elucidate the fiber–matrix interaction mechanism.

Concrete by Preplaced Aggregate Method Using Silica Fume and Polypropylene Fibres.

Preplaced aggregate concrete (PAC) is prepared in two steps, with the coarse aggregate being initially laid down in the formwork, after which a specialised grout is injected into it. To enhance the properties of concrete and to reduce the emission of CO2 produced during the production of cement, supplementary cementitious materials (SCMs) are used to partially substitute ordinary Portland cement (OPC). In this study, 100 mm × 200 mm (diameter x height) PAC cylinders were cast with 10 per cent of cement being substituted with silica fume; along with that, 1.5% dosage of Macro polypropylene fibres were also introduced into the coarse aggregate matrix. Compressive strength test, splitting tensile strength test, mass loss at 250 °C, and compressive strength at 250 °C were performed on the samples. PAC samples with 10% of cement replaced with Silica Fume (SPAC) were used as control samples. The primary objective of this study was to observe the effect of the addition of Polypropylene fibres to PAC having Silica fume as SCM (FRPAC). The aforementioned tests showed that FRPAC had a lower compressive strength than that of the control mix (SPAC). FRPAC had greater tensile strength than that of NPAC and SPAC. Mass loss at 250 °C was greater in SPAC compared to FRPAC. The compressive strength loss at 250 °C was significantly greater in FRPAC compared to SPAC. FRPAC exhibited a greater strain for the applied stress, and their stress-strain curve showed that FRPAC was more ductile than SPAC.

Evaluation of slag/fly ash based geopolymer concrete with steel, polypropylene and polyamide fibers

Geopolymer composites have become an essential product to reduce CO2 emissions, which is an important problem today and ensures green sustainability. With the increasing concerns with global climate change, studies on geopolymer have also increased. The addition of different fibers also has essential potential for increasing the performances of geopolymer composites. Within the scope of this study, it is aimed to produce a green sustainable product as an alternative to traditional concrete by producing different fiber-reinforced geopolymer concrete. In this study, slag-fly ash-based geopolymer concretes reinforced with three different fiber types (Polypropylene (PP), steel (ST), and polyamide (PA)) were produced and the mechanical properties such as compressive, tensile, drying shrinkage and flexural behavior were investigated. Furthermore, elevated temperature (300, 600 and 900-celsius degrees) and freeze-thaw (250 cycles) tests were carried out within the scope of durability properties. Microstructural analyzes were also carried out to understand the matrix composition. Experimental test results revealed that fiber reinforcement improved some of the strength properties, but was ineffective for some properties. The addition of polypropylene and steel fibers significantly improved the flexural toughness factor value (1469% and 566%, respectively) of geopolymer concretes, while this rate of improvement remained quite low (46%) in the polyamide fiber reinforced geopolymer series. According to shrinkage test values, 50S50FA08ST sample ranged from 264 to 297 microstrains. Also, PP fibers increased the initial crack load from approximately 4500 N to 6750 N and the deflection values significantly improved by reaching the deflection values of 7.5 mm. Moreover, the compressive strength values after 900 °C was obtained as 11–12 MPa for steel fiber reinforced geopolymer concretes. But the freeze–thaw experiments generally revealed that fiber addition did not contribute to the improvement of strength properties.

Effects of high–low temperature cycles on the performance of coral aggregate concrete based on field specimens and laboratory accelerated tests

In the high-temperature marine environment, breakwaters frequently suffer from high–low temperature cycles, which inevitably damages the performance of coral aggregate concrete (CAC). Based on field specimens and laboratory tests, in this research, the evolution of macroscopic and microscopic properties, as well as the crack density of CAC under high–low temperatures action were investigated, then the damage mechanism of CAC was revealed. The experimental results showed that the compressive strength of the specimens derived from the outside and top surface of on-site breakwater ranged from 24.07 to 55.48 MPa and from 26.26 to 43.41 MPa, respectively, and their splitting compressive strengths ranged from 1.29 to 4.65 MPa and from 1.68 to 4.49 MPa, respectively. In addition, fine cracks and swelling products can be found in the CAC. Under the indoor accelerated test of seawater cooling, the compressive strength of the indoor CAC developed in an increasing and then decreasing trend with the increase of the cycle period, whereas the splitting tensile strength kept developing in a decreasing trend, this was caused by the dual action of high–low temperatures cycles and sulfate erosion. Additionally, the interior of CAC also exhibited more calcium alumina, gypsum, and sodium sulfate crystal. Moreover, the addition of fly ash (FA), silica fume (SF), and polypropylene fiber (PF) can reduce the strength loss of CAC under high–low temperature cycles to some extent. The mathematical relationship between the relative dynamic elastic modulus of the CAC and the cycle period could be fitted by a quadratic polynomial (Erd = a + bt + 0.5ct2, R2 greater than 0.99).

Effect of Stress–Strength Ratio and Fiber Length on Creep Property of Polypropylene Fiber-Reinforced Alkali-Activated Slag Concrete

Alkali-activated slag (AAS) is an environmentally friendly green cementitious material that can replace ordinary Portland cement (OPC) and has attracted extensive research by scholars all over the world. However, research regarding its creep performance has been lacking, which in turn affects its further application. The creep of alkali-activated slag concrete is large, and fiber addition has been shown to improve this problem. Polypropylene (PP) fiber has good alkali resistance and is economical. This paper studies the effect of the stress–strength ratio and fiber length on the creep property of PP fiber-reinforced alkali-activated slag (FRAAS) concrete. At the stress–strength ratio of 0.15, PP fiber addition is able to greatly reduce the creep of concrete. When the stress–strength ratio increases, the shorter fiber loses the anchoring force and the holes caused by the longer fiber crack. This in turn leads to the deterioration of the inhibition effect on concrete creep. The CEB-FIP 2010 model is highly accurate, but the final value prediction is small. The early prediction value of the GL2000 model is rather large and conservative. The creep coefficient of the prediction model and the measured secant modulus of PP FRAAS concrete with different fiber lengths under different stress–strength ratios may solve the issue of creep prediction.

Study on the non-linear deformation and failure characteristics of EPS concrete based on CT-scanned structure modelling and cloud computing

To understand the complex deformation features and failure mechanisms of expanded polystyrene (EPS) concrete and reveal the composite effect of expanded polystyrene beads and polypropylene fibers, a series of experiments were conducted on the poured EPS concrete specimens. Meanwhile, a cloud computing system for 3D realistic failure process analysis (RFPA3D) was established to model the fine failure process of a real concrete structure. The micromorphology of the EPS concrete specimens was obtained via CT scanning and further processed using digital image processing technology. The Otsu algorithm was applied to automatically recognize the segmentation thresholds of each partition image and a procedure for CT image processing was designed to automatically realize digital image segmentation and merging. Then, the numerical models reflecting the microstructures of the EPS concrete specimens were built using the processed digital images and a series of 3D numerical simulations were performed using cloud-computing-based RFPA3D. The results show that for concrete with low EPS volume fracture, the non-smooth convex-step-shaped failure morphology, which is a typical brittle fracture characteristic, appears. In contrast, ductile fracture occurs for concrete with a high EPS volume fracture. Simultaneously, the addition of polypropylene fibers of a certain length can effectively prevent the formation and expansion of new cracks in the cement matrix. In addition, the peak strength of concrete increases with an increase in homogeneity while the residual strength generally decreases with an increase in homogeneity. Moreover, a more heterogeneous material presented more acoustic emission precursors before macro fracture. All these achievements greatly improve our knowledge of the design, construction, and maintenance of EPS concrete in civil engineering.

Effect of fibers on stress–strain behavior of concrete exposed to elevated temperature

Addition of fiber enhances the engineering properties of concrete. Effect of elevated temperatures on the compressive strength and stress–strain relationship of concrete are presented in this paper. The behavioral efficiency of fiber reinforced concrete (FRC) is far superior to that of plain concrete and many other construction materials of equal cost. Aim of this study is to evaluate the mechanical properties of various fiber reinforced concrete systems, containing individual steel fibers (SF), polypropylene (PP) fibers and hybrid combination of steel and PP fibers with and without exposed to elevated temperature. The total dosage of fibers in concrete was maintained as 0.5%, 1%, 1.5% & 2%. Specimen with 2% SF achieved a maximum compressive strength of 40 MPa before heating, and fiber content with 1.5% of concrete exposed to 1 h duration (925 °C) possess a maximum strength of 28.92 MPa. Addition of PP fibers with 0.5–2% shows marginal variation in compressive strength, maximum strength of 28 MPa is achieved for 1.5% fiber content before heating. Specimen subjected to elevated temperature with 1.5% PP shows a maximum strength of 20 MPa. Hybrid fiber (SF + PP) exhibited a maximum strength of 36 MPa for 2% fiber content before heating, whereas after heating the concrete attains a strength of 24.96 MPa. Contribution of PP fiber in preventing micro-cracks was more pronounced for concrete exposed to 1 h duration.

An Artificial Neural Network Based Prediction of Mechanical and Durability Characteristics of Sustainable Geopolymer Composite

Despite the growing environmental consequences of cement production, geopolymer concrete now has gradually evolved as an ecologically sustainable product. This study experimentally investigates the effect of addition of different proportions (0%, 10%, and 20%) of rice husk ash (RHA) and polypropylene (PP) fibers (0%, 0.1%, and 0.3%) on the mechanical and durability characteristics of fly ash (FA)‐based geopolymer mortars. The strength property is assessed by testing the mortar specimen by uniaxial compressive strength and flexural strength while the durability properties were tested with water absorption, water sorptivity, and acid (10% concentration of H2SO4) resistance tests. The experimental findings revealed that the PP fiber addition is not significant in improving the compressive strength, while the addition up to 0.3% by volume had shown good improvement in flexural behavior. Water absorption increases with an increment in the replacement proportion of RHA. Water sorptivity also increases with an increase in RHA substitution levels. Furthermore, an artificial neural network prototype was proposed in this work to forecast the mechanical and durability properties of fiber reinforced FA‐RHA blended geopolymer mortar. The ANN architecture was constructed utilizing the mechanical and durability characteristics of FA‐RHA blended geopolymer mortar procured through experimental investigation. The RHA substitution proportion, sodium hydroxide (NaOH) liquid concentration, and polypropylene fiber content have been employed as input parameters in the construction of ANN framework. The predicted strength values of mechanical and durability tests achieved from the ANN framework agree well with experiment results. Use of geopolymer mortar has a high potential in repairing the structural elements, and further studies can be done on applying this mortar for the repairs.

Influence of fibers on fresh properties and compressive strength of geo-polymer concrete

Geopolymer concrete (GPC) is a sustainable construction material that can be used as a substitute for conventional cement concrete. Several factors influence the performance of GPC such as, the type of binder material used, the molar concentration of the activator solution, and the curing conditions. The main purpose of this work is to develop fiber reinforced GPC by utilising various fibers that to reduce brittleness. The proposed work is divided into two phases. In the first phase, experiments are conducted to evaluate the significant impact of partial replacement of Ground Granulated Blast Furnace Slag (GGBS) with low-calcium fly ash on workability and compressive strength of GPC optimizing the amount of GGBS required for the development of M35 and M40 grade GPC under ambient curing. In the second phase, the performance of crimped steel fiber, polypropylene fiber and basalt fiber in terms of workability and compressive strength were evaluated. Crimped steel fiber containing by volume of binder (0.4%, 0.45%, 0.5%, 0.55% and 0.6%), polypropylene fiber containing by volume of binder (0.05%, 0.1%, 0.15%, 0.2% and 0.25%) and basalt fiber containing by volume of binder (0.1%, 0.15% 0.2%, 0.25%, 0.3% and 0.35%) are used in the experiment. NaOH with 8 M and 12 M with Na2SiO3 were used as an alkaline solution to develop GPC and cured in the ambient curing for 7 days and 28 days respectively. It was observed that increase in the percentage of GGBS decreased the workability, but the compressive strength is increased. The effect of fibers on workability and compressibility has been observed, and it has been found that workability decreases with the increase of fibers in the GPC. Compare to crimped steel fiber, basalt fiber the workability of GPC is highly affected due to the addition of polypropylene fiber. In comparison crimped steel fiber and polypropylene fiber, concrete with salt fiber exhibited higher compressive strength.