Increase In Split Tensile Strength Research Articles

An investigation of waste glass powder with the substitution of sand on concrete mix

Waste glass makes a considerable contribution to a number of critical environmental problems of which the majority are caused by glass waste streams that lack cohesion. The concrete industry has developed a variety of strategies in response to mounting environmental pressure to cut down on trash and increase recycling rates. Newly poured, rock-solid concrete was used for testing. Aim of this study was to examine impact of employing discarded glass as fine aggregate on concrete properties. Waste glass content was taken into account while assessing the attributes of strength. In concrete compositions, general waste glass powder was used in place of sand at percentages of 10 %, 15 %, and 20 %, respectively. The findings of slump value test demonstrated that adding more waste glass powder to concrete mix raised value. When waste glass powder was utilized to replace 15 % of the sand in the combination of concrete materials, both the concrete's compressive and tensile strengths increased. After 28 days of curing, there was a maximum increase in split tensile strength of 11.28 % and a maximum improvement in compressive strength of 17.05 % when compared to standard concrete. The amount of waste glass powder in concrete mixture also decreased material's ability to absorb water.

An appraisal of the mechanical, microstructural, and thermal characteristics of concrete containing waste PET as coarse aggregate

• Heat-processed PET-modified concrete is appropriate for strutural applications. • Heat-processed PET-modified concrete is visible, and suitable as it conserves natural resources. • Heat-processed PET aggregate is sustainable as it substitues natural aggregaes with waste plastics. This study assessed the workability, mechanical, microstructural, and thermal behaviours of concrete composed from recycled waste polyethylene terephthalate (PET) as a partial or full replacement for natural coarse aggregates. Workability and Compressive/Split tensile strength tests alongside microstructural and thermogravimetric analysis were performed. Results disclosed that the concrete’s workability increased with increasing percentages of PET. The compressive strength increases with extended curing but decreases as the percentages of waste PET increased at different curing lengths. The PET-modified blends could not yield the target design strength for grade 25 concrete after 28 days. However, the 20% PET-modified mix reached the target strength for concrete grade 20. For all blends, increase in split tensile strength with curing lengths was observed, only the 20% PET-modified blend achieved suitable split tensile strength values. Microstructural analysis revealed that the 100% PET sample has a relatively irregular surface pattern with pores of about 2–4 µm, high quantities of Ca, and minor traces of O, C, Al, Si, Mg, and Na. While PC-20 had a much denser interface between the PET aggregates and the cement matrix with high percentage of Si, O, and Ca, and moderate to minor percentage of Al, Au, Na, and Mg. Thermal analysis showed that the 100% PET sample endured three transition stages. The research outcomes prove that heat-processed PET-modified concrete is suitable for structural applications due to its acceptable fresh, mechanical, microstructural, and thermal properties. Moreover, this alternative is eco-friendly and sustainable as it substitutes natural aggregates with waste plastics.

Evaluation of strength characteristics and identifying the optimum dosage with the impact of partial replacement of recycled fine and coarse aggregate from construction and demolition waste

Natural Sand as fine aggregate (FA) and different sizes and forms of gravel or stones as a coarse aggregate (CA) are used in traditional concrete. Alternative aggregate elements, primarily as a potential application for recycled resources, are gaining in popularity. Although many new types of aggregate substitutes are being studied, along with granulated slag, rice husk ash, or multiple industrial wastes like fiberglass waste products, finely ground plastics, paper, and wood products or wastes, sintered sludge granules, and many others, there is now a lot of work to be done. This study is taken up to utilize the recycled coarse aggregate (Rca) and recycled fine aggregate (Rfa) as a replacement for natural aggregate (NA) in concrete mix and required to find the percentage of Rca and Rfa, as the strength of concrete cannot be achieved by using higher percentage. The purpose of the study is to compare recycled coarse aggregate (Rca) and recycled fine aggregate (Rfa) with natural coarse aggregate (Nca) and sand in terms of specific gravity, water absorption, particle size dissemination. Further, this study will also consider the difference between the performance of Recycled Aggregate Concrete (RAC) for different percentages of recycled coarse aggregate (Rca) and recycled fine aggregate (Rfa) i.e., for 0%, 10%, 15%, 20%, 25%, 30%, 35% replacement. The present study is an investigational study on the behavior of recycled aggregate concrete indicating coarse and fine aggregates for the strength, also identifying the optimum dosage of Rfa, Rca, Nca and Nfa with their performance levels and the relationship between compressive strength (CS), Split Tensile Strength (STS) and Flexural Strength (FS). It has been observed that optimum dosage of Recycled Aggregate proportion has been identified as M1 with Cement + 90% Nfa + 90% Nca + 10% Rfa + 10% Rca + W + 1% SP in CS with 40 N/mm2 and 20% increase in STS and 16% decrease in FS compared with Conventional Concrete (CC).

Study on Steel and polypropylene hybrid fiber reinforced concrete– A review

Increasing demand and inadequate materials availability leads the researchers to find alternate materials. In general, hybrid fiber is nothing but mixture of two or more fibers. In this review, various properties of steel fibers and polypropylene fibers were studied. In order to study the physical and mechanical properties of steel fiber, polypropylene fiber and other materials used in concrete, various tests such as Slump cone test, Compaction factor, Compressive strength , flexural strength etc., were used. Hybrid fibers have the tendency to control cracks at different levels. Workability of concrete get reduced due to more addition of steel fibers.The addition of steel fiber and polypropylene fiber results in an increase of 12 to 14.30% compressive strength, 33 to 36.6% increase in flexural strength and 9 to 10.16% increase in split tensile strength. Addition of most favorable amount 0.9 to 1% of steel fiber and 0.9 to 1% of polypropylene fiber gives maximum compressive strength up to 41.67 to 42.68%. Split tensile strength increases by increasing the fiber content in concrete but workability decreases when steel fiber content is increased in concrete.

Mechanical and Material Properties of Mortar Reinforced with Glass Fiber: An Experimental Study.

The progressive increase in the amount of glass waste produced each year in the world made it necessary to start the search for new recycling methods. This work summarizes the experimental results of the study on mortar samples containing dispersed reinforcement in the form of glass fibers, fully made from melted glass waste (bottles). Mortar mixes were prepared according to a new, laboratory-calculated recipe containing glass fibers, granite as aggregate, polycarboxylate-based deflocculant and Portland cement (52.5 MPa). This experimental work involved three different contents (600, 1200, and 1800 g/m3) of recycled glass fibers. After 28 days, the mechanical properties such as compressive, flexural, and split tensile strength were characterized. Furthermore, the modulus of elasticity and Poisson coefficient were determined. The initial and final setting times, porosity, and pH of the blends were measured. Images of optical microscopy (OM) were taken. The addition of glass fibers improves the properties of mortar. The highest values of mechanical properties were obtained for concrete with the addition of 1800 g/m3 of glass fibers (31.5% increase in compressive strength, 29.9% increase in flexural strength, and 97.6% increase in split tensile strength compared to base sample).

Performance of Lightweight Aggregate Concrete Containing Expanded Polystyrene, Cinder and Ground-Granulated Blast-Furnace Slag

Lightweight aggregate concrete is developed by substituting normal weight aggregate either fully or partially based on strength and density required. Expanded polystyrene (EPS) bead is a type of low density material, which also has good energy-absorbing characteristics and can be used as light weight aggregate in concrete. In the present study, Structural lightweight aggregate concrete (SLWAC) was produced by fully replacing normal weight aggregate with combinations of EPS beads to Cinder by the ratio 20:80, 40:60, 60:40, 80:20 respectively. And GGBS was used as supplementary cementitious material. The resulting concrete had strength variation between 29.5 to 11.6 MPa, and the density variation of 2192 to 1701 kg/m3. Considering strength and density criteria 40:60 ratios was observed as the optimal mix. The Compressive strength acquired by concrete was inversely proportional to the volume of EPS beads. Effect of fibers on mechanical properties such as flexural strength, compressive strength, and split-tensile strength was studied on the optimal mix by using polypropylene fibers, it was observed that an 8.78% increase in flexural strength at 1% fibers, 16.5% increase in Compressive strength at 0.5% fibers, and 35.4% increase in split-tensile strength at 1% fibers. Along with this, durability tests such as water absorption and permeability tests were performed, the performance of this concrete in water absorption test is well within the limits but in permeability, it underperformed which confirms that as the EPS ratio in the concrete increased, the absorption and depth of penetration values increased considerably. Microscopic observations were also made to study the interface amongst the cement paste and aggregates. It was revealed that GGBS did not influence significantly on the bonding with EPS beads.

Performance of Lightweight Aggregate Concrete Containing Expanded Polystyrene, Cinder and Silica Fume

Lightweight aggregate concrete is developed by substituting normal weight aggregate either fully or partially based on required strength and density. Expanded polystyrene (EPS) bead is a type of low density material, which also has good energy-absorbing characteristics and can be used as light weight aggregate in concrete. In the present study, Structural lightweight aggregate concrete (SLWAC) was produced by fully replacing normal weight aggregate with combinations of EPS beads to Cinder by the ratio 20:80, 40:60, 60:40, 80:20 respectively and Silica fume was used as supplementary cementitious material. The resulting concrete had strength variation between 24.85 to 12.01 MPa, and the density variation of 1896 to 1664 kg/m3. Considering strength and density criteria 40:60 ratios was observed as the optimal mix. The Compressive strength acquired by concrete was inversely proportional to the volume of EPS beads. Effect of fibres on mechanical properties such as flexural strength, compressive strength, and split-tensile strength was investigated on optimal mix by using polypropylene fibres, it was observed that a 13.24% increase in flexural strength at 1% fibres, 8.41% increase in Compressive strength at 1% fibres and 23.11% increase in split-tensile strength at 1% fibres. Along with these, durability tests such as water absorption and permeability tests were performed, the performance of this concrete in water absorption test and permeability is well within the acceptable limits as the EPS ratio in the concrete increased, the absorption and depth of penetration values increased considerably. Microscopic observations were also made to study the interface amongst the cement paste and aggregates. It was revealed that silica fume has influenced significantly in bonding with EPS beads.

Characteristics of Recycled Polypropylene Fibers as an Addition to Concrete Fabrication Based on Portland Cement

High-performance concrete has low tensile strength and brittle failure. In order to improve these properties of unreinforced concrete, the effects of adding recycled polypropylene fibers on the mechanical properties of concrete were investigated. The polypropylene fibers used were made from recycled plastic packaging for environmental reasons (long degradation time). The compressive, flexural and split tensile strengths after 1, 7, 14 and 28 days were tested. Moreover, the initial and final binding times were determined. This experimental work has included three different contents (0.5, 1.0 and 1.5 wt.% of cement) for two types of recycled polypropylene fibers. The addition of fibers improves the properties of concrete. The highest values of mechanical properties were obtained for concrete with 1.0% of polypropylene fibers for each type of fiber. The obtained effect of an increase in mechanical properties with the addition of recycled fibers compared to unreinforced concrete is unexpected and unparalleled for polypropylene fiber-reinforced concrete (69.7% and 39.4% increase in compressive strength for green polypropylene fiber (PPG) and white polypropylene fiber (PPW) respectively, 276.0% and 162.4% increase in flexural strength for PPG and PPW respectively, and 269.4% and 254.2% increase in split tensile strength for PPG and PPW respectively).

Impact of Bacillus subtilis bacterium on the properties of concrete

The activity life span of concrete sharply decreases with the formation of cracks on its surface which leads to corrosion of concrete. To deal with such problems newer technologies are being adopted for concrete production and one such high-tech concrete is self-healing concrete by Microbiologically Induced Calcite Precipitation (MICP). This kind of concrete can initiate biological activity to deal with its cracks and to recover itself. This research paper throws light on the experimental investigation carried out to evaluate the impacts of Bacillus subtilis bacteria on concrete properties. The experiment has been carried out using six different bacterial concentrations in the concrete mixes, such as 10, 102, 103, 104, 105 and 106 cells/ml of water. Concrete specimens were left for 7 days, 14 days and 28 days of curing. Tests were conducted for measuring properties like compressive strength, split tensile strength, flexural strength were measured in different interval of curing period. The research showed that concrete having bacterial infusion in all cell concentration have increment in strength in comparison to control mix. Maximum of 32% increase in compressive strength, 14% increase in split tensile strength and 29% increase in flexural strength were observed in the specimen having bacterial concentration of 105 cells/ml of water. Microbial calcite precipitation was visualized by Scanning Electron Microscopy (SEM), which showed the growth of filler materials i.e. calcite deposition inside the concrete pores, which results in denser concrete causing a rise in its strength.

Impact of Combination of Natural and Synthetic Fibers on the Mechanical Properties of Concrete

Concrete has found its widespread application as a construction material. The use of different kinds of concrete have revolutionized the construction industry. Concrete as we know is very good in compression, however due to the development of micro cracks under tensile loading in concrete, the tensile strength of concrete is only 1/10th of its compressive strength. This drawback of concrete has been taken care of by the use of reinforcement in concrete. Rebars or reinforcement bars along with the concrete have added much to the tensile strength of concrete. Over the years steel bars, steel fibers and other materials have been used as reinforcement in concrete. Use of reinforcing bars in concrete caters the need of resisting tensile loads and thereby making Reinforced Cement Concrete an excellent construction material. However, the use of heavy steel bars as reinforcement makes concrete structures heavy and difficult to handle. In order to take care of this a new concept of reinforcement has been introduced i.e. reinforcing concrete with fibers. Different types of fibers have been used over the years as reinforcement in concrete. In this experimental study, combinations of two fibers have been used as a reinforcement. One of the fibers is a natural fiber i.e. coconut fiber and other one is a synthetic fiber i.e. polypropylene fiber. Both these fibers are used in combination with a specific percentage. In the first sample 0.5% of recron fiber was used and 0.25% of coconut fiber. In second sample 0.5% recron fiber was used and 0.75% of coconut fiber. The fiber reinforced concrete was then tested for compressive as well as tensile strength. The test results showed 29.4% and 5.3% increase in compressive strength, 32.3% and 48.9% increase in split tensile strength and 40% and 80% increase in the flexural strength of concrete for both combinations respectively. Thus, making the concrete light weight and more resistant to cracking. This could be very useful in case of concrete pavements and slabs.

The Effect on Strength of Concrete by Partial Replacement of Cement and Fine Aggregate with Flyash, Granite Powder and Plastic Fibres

The rapid growth of the population leads to a requirement of infrastructure this leads to scarcity of raw material for construction such as cement and sand. The other hand pollution growing due to thermal power plants, granite polishing unit and plastic waste this need to be removed. This gives an idea of using this compound as a raw material in concrete making. This concept found to effective minimizes disposal of fly, granite power and plastic wastes, and leads towards Green Building Concepts. In this investigation of M25 grade normal concrete is made by cement, sand, and aggregate which is tested and compared by special concrete. The concrete mix is prepared as per 10262 -2019 by adding replacing small amount of Fly ash in place of cement OPC 53 grade, and fine aggregate is prepared by partial replacing with granite powder (0%,10%,20%,30%)and another mix is prepared by adding 0.5 nylon fiber, partial replacement of fine aggregate with granite powder (0%,10%,20%,30%)specimens are casted . The casted specimens are tested for split tensile strength and compressive strength 7, 14 and 28 day’s respectively and these results also compared with each other. I t is observed that compressive strength and split tensile of concrete at 28days of curing show max value when compared with normal concrete. When the percentage of granite powder increases to 30% it shows that a decrease in both split tensile strength of concrete and compressive strength. When we added fiber to the concrete there is an increase in compressive strength and split tensile strength but there is a not much increase in compressive strength but increase in split tensile strength

Influence of different treatment methods on the mechanical behavior of recycled aggregate concrete: A comparative study

Recycling of construction and demolition waste in the concrete is considered a sustainable way However, recycled aggregates (RA) with inferior properties are produced after recycling as compared to natural aggregates. This study aims to improve the performance of RA by utilizing different treatment methods and to evaluate the properties of the resulting recycled aggregate concrete (RAC). For this purpose, five different treatment techniques of RA, such as carbonation, acetic acid immersion, acetic acid immersion with mechanical rubbing, acetic acid immersion with carbonation and lime immersion with carbonation are adopted during the study. Different mechanical tests are performed to investigate the effect of different RA treatment techniques on the mechanical properties of RAC with treated and untreated RA. Increase in split tensile strength and flexural strength along with improved stress-strain behavior of RAC is observed for treated RA as compared to untreated RA. The stress-strain behavior of RAC having RA treated through acetic acid immersion with mechanical rubbing and lime immersion with carbonation is observed very close to the stress-strain curves of natural aggregate concrete reflecting the positive impact of these RA treatment techniques on the performance of RAC. Moreover, empirical relations to predict different mechanical properties and stress-strain model of RAC with both treated and untreated RA are also developed in this work. A comparative study of the existing and proposed models with the test results indicates that the proposed relations and model can effectively predict the mechanical behavior of RAC with both treated and untreated RA.

Application of Recycled PET Fibers for Concrete Floors

High consumption of plastics leads to production of large amounts of plastic waste. Plastic is non-biodegradable so its disposal has been a problem. In order to resolve this problem, recycled PET fibers were proposed to be used as reinforcement in concrete. This paper has discussed the effect of adding Polyethylene terephthalate (PET) fiber to the blended cement mixed concrete floor slab panel. This research consists of two main stages. In first stage, different volumes of recycled PET fibers, i.e. 0%, 0.5%, 1.0% and 1.5% have been added as percentages of concrete by volume. The results showed that the maximum volume of PET fiber for a desired compressive and tensile strength was 1.0%. It was observed that 15.3 % of increase in compressive strength, 22.44% of increase in flexural strength and 18.77% of increase in split tensile strength for the addition of 1.0% PET fibers to the concrete. In second stage, optimum fiber percentage (1.0%) selected from the first stagewas used to produce slab panels. Inorder to investigate the structural performances of the slab panel, center-point line loading test, dropping weight test and energy absorption test were conducted. It has been found that recycled PET fiber introduced slab panels showed better performance compared to the conventional floor slab panel.

Split tensile strength of monofilament polypropylene fiber-reinforced cemented sandy soils

ABSTRACT: The present research aims to quantify the influence of the amount of cement, the porosity, and the voids/cement ratio in assessment of the split tensile strength (qt) of a sandy soil when reinforced and non-reinforced with fibers. A series of split tensile tests were carried out in the present work. The results show that fiber insertion in the cemented soil, for the whole range of cement studied, causes an increase in split tensile strength. The split tensile strength (qt) increased linearly with the amount of cement (C), and a power function fits well as the relation between split tensile strength (qt) and porosity (η) for both the fiber-reinforced and non-reinforced specimens. It was also shown that the voids/cement ratio, in which volumetric cementitious material content is adjusted by an exponent (0.28 for both the fiber-reinforced and non-reinforced cemented soil mixtures) to result in unique correlations for each mixture, is a good parameter in the evaluation of the split tensile strength of the fiber-reinforced and non-reinforced cemented soil studied. This experimental framework will enable a good definition of mechanical parameters used in the design of foundations and subgrades of roads and railways platform (whose system failure mechanisms usually start under tensile stresses at the base of the improved layer) and for their execution quality control.