Splitting Tension Strength Research Articles

Assessing the role of polypropylene fibres on tensile strength of alccofine and silicafume blended high strength concrete

In the present study, the M40 grade of concrete is designed with binder materials comprising of 70% cement and 30% Supplementary Cementitious Materials (SCM). Of the 30% SCM, flyash C (FA) accounts for 20% whereas the remaining 10% is either Silicafume (SF) or Alccofine (AL), respectively. In addition to binder materials, the polypropylene fibres with weight proportions ranging from 0 to 0.5% of binder materials is added. For unreinforced specimens, the split tension strength at 28 and 90 days curing period is 3.80 and 4.36 MPa, respectively for AL blended concrete whereas it is 3.93 and 4.16 MPa for SF blended concrete. For incrementing proportion of polypropylene fibres, the split tensile strength and strain energy of both SF and AL blended concrete increases with increasing curing period. For AL blended concrete, the increment in tensile strength at 90 days curing period ranges from 6 to 20% while the strain energy increase is upto 120%. The study confirms that the inclusion of polypropylene fibres is more effective towards improving tensile strength and energy absorption capacity of AL blended concrete than SF blended concrete. In addition to tensile strength and strain energy, optical microscopy images have been used to evaluate the effect of polypropylene fibres on porosity and calcium hydroxide (CH) content.

An Eco Friendly Geopolymer Concrete with Nylon Crystal Replacement

Abstract: Concrete has occupied a crucial place in housing industry within the past few decades and it's used wide altogether kinds of constructions starting from little buildings to massive infrastructural dams or reservoirs. Cement is major element of concrete. the value of cement is increasing day by day because of its restricted availableness and huge demand. At a similar time the world warming is increasing day by day. producing of cement additionally releases greenhouse gas. within the gift study an endeavor been created on concrete ANd additionally an experimental investigation on the concrete mistreatment by commutation cement with FLYASH and GGBS to avoid the usage of cement also as emission of inexperienced house gases within the gift study an endeavor been created on geopolymer concrete with nylon crystals.And additionally AN comparative study of this gpc with standard M20 concrete Experimental studies were performed on plain geopolymer concrete and replacement of cement with Nylon crystal is completed. during this study the concrete combine were ready by mistreatment flyash, glass, hydroxide and Nylon crystal from 100% to four-hundredth by weight of flyash were superimposed part to the mixes. A comparative analysis has been meted out for M20concrete to it of the Nylon crystal bolstered geopolymer concrete in regard to their compressive strength, split tension strength and flexural strength properties. The geopolymer concrete created with Nylon crystal performed well in terms of compressive strength, split tension strength and flexural strength showed higher performance at the age of seven, 28, sixty and ninety days than typical concrete. And additionally 2 differing types of acid attack is completed to see the Bond Strength and compressive strength each on typical concrete and Nylon crystal bolstered geopolymer concrete.

AN INVENTIVE CONCRETE PAVEMENT BY USING NYLON CRYSTAL AS A PARTIAL REPLACEMENT OF CEMENT

Transportation is a major developing sector in India, and required for good quality of roads, railways and airways is high. Concrete has occupied an important place in construction industry in the past few decades and it is used widely in all types of constructions ranging from small buildings to large infrastructural dams or reservoirs. Cement is major ingredient of concrete. The cost of cement is increasing day by day due to its limited availability and large demand. In the present study an attempt been made on concrete and also an experimental investigation on the concrete using Nylon Crystal. Experimental studies were performed on plain cement concrete and replacement of cement with Nylon crystal is done. In this study the concrete mix were prepared by using Nylon crystal from 1% to soon by weight of cement were added partially to the mixes. A comparative analysis has been carried out for concrete to that of the Nylon crystal reinforced concrete in relation to their compressive strength, split tension strength and flexural strength properties. The concrete made with Nylon crystal performed well in terms of compressive strength, split tension strength and flexural strength showed higher performance at the age of 7, 28, 60 and 90 days than conventional concrete. And also Bond Strength by using cylinders and two different types of acid attack is done to determine the Bond Strength and compressive strength both on conventional concrete and Nylon crystal reinforced concrete. Key Words: Acid Attack, Bond Strength, Compressive Strength, Flexural Strength, Nylon Crystal, Split Tensile Strength.

Effect of brick waste content on mechanical properties of mixed recycled concrete

The main compositions of recycled coarse aggregate produced from demolition waste of brick-concrete construction are recycled concrete coarse aggregate (RCCA) and recycled brick coarse aggregate (RBCA), called mixed recycled coarse aggregate (MRCA). This paper presents the results of test on the specific density (SD), saturated surface dry density (SSD), water absorption (WA), crushing value (CV) of twenty-three groups of MRCA and slump, SSD, cubic compressive strength (fcu), splitting tension strength (fts), static modulus of elasticity (Ec), flexural strength (ff) of the corresponding MRCA concretes. The results show that the correlation between WA of MRCA and RBCA content is the strongest, followed by SSD and WA of MRCA. A continuous decrease in SSD and a continuous increase in WA and CV can be observed with the increase of RBCA content, however, the SD has no obvious change with the increase of RBCA content when the SD is measured by drainage method. The cubic compressive strength and elastic modulus of MRCA concretes always decrease linearly with the increase of RBCA content, and the RBCA content has no obvious effect on the splitting tension and flexural strength in case the total amount of RCCA and RBCA is no more than 30%. According to the good correlation between the RBCA content and the properties of MRCA and MRCA concrete, the prediction model of WA, CV, and SSD of MRCA and fcu, Ec, and fts of MRCA concrete are established based on the RBCA content.

A novel approach on properties of internal curing concrete and impact of salts

The curing process for massive and inaccessible structures is troublesome. To overcome this difficulty and to reduce the evaporation by increasing the performance of mechanical properties, the process of internal curing is the superlative method. This research is aimed to investigate the mechanical and salt properties of Internal Cured Concrete prepared using Polyethylene Gylcol - 600. M25 grade concrete is prepared at various proportions of PEG viz., 0%, 0.5%, 1%, 1.5% and 2% by cement weight. The average maximum compression and flexural strengths were observed at 2% of PEG solution, while the maximum split tension strength was recorded at 1.5% of PEG. NaCl, KCl solutions are used to investigate the influence of salts. The specimens were prepared by utilising the mix that resulted the maximum compressive strength. The specimens are then immersed in both salts for 14 days and the results are evaluated. It was observed that, both the chemicals have shown hostile effect on concrete prepared using PEG-600 solution resulting in deterioration.

Characteristics of Recycled Aggregate Concrete Produced with Crushed Stone Sand as Fine Aggregate

In this work the characteristics of recycled aggregate concrete produced with crushed stone sand as 100% replacement of desert stone were experimentally investigated. Concrete mixtures incorporating varying percent replacement of normal aggregate with recycled aggregate as coarse aggregate and crushed stone sand as fine aggregate were produced and tested at 7, 28, 56 and 90 days of concrete age for various hardened concrete properties. For one-on-one comparison, corresponding recycled aggregate concrete mixtures using desert sand as fine aggregate were also tested. Superior performance of crushed stone sand-based concrete mixtures was recorded for compressive and flexural strengths, static modulus of elasticity, abrasion resistance and water absorption characteristics when compared with that of the corresponding recycled aggregate concrete mixtures produced with desert sand as fine aggregate. No significant effect of crushed stone sand was recorded on the split tension strength of concrete mixtures. Improvement in mechanical properties and water absorption characteristics of crushed stone-based mixtures was, however, observed up to 50 wt.% replacement level of normal aggregate with recycled aggregate. Beyond this level of replacement, no noticeable difference in the performance of the two categories of recycled aggregate concrete mixtures was recorded. It is concluded that crushed stone sand can be effectively used as fine aggregate replacing desert sand to avoid the limitations caused in the mechanical properties of recycled aggregate concrete mixtures due to the use of desert sand as fine aggregate.

Effect and mechanism of acidic aggregate surface silane modification on water stability of asphalt mixture

This study assessed the water stability of asphalt mixtures incorporating granite aggregates. A silane coupling agent was adopted to modify the surface of the granite aggregates, and scanning electron microscopy, contact angle measurements, Fourier transform infrared spectroscopy, and X-ray fluorescence were used to analyze the micro- and meso-characteristics of the aggregates. Effects of the silane treatment on the water stability of the mixtures were further evaluated by immersion and vacuum saturation Marshall tests and freeze–thaw splitting tests. The results indicated that the silane coupling agent had grafted onto the aggregate surface via chemical interactions, resulting in obviously raised contact angles and greatly reduced hydrophilicity. Additionally, the deposited organic film also reacted with the asphalt and formed a tighter bonding interface between the asphalt and aggregates, resulting in an asphalt mixture with a higher residual stability and splitting tension strength ratio when under environmental stress.

Mechanical properties of concrete with small fibre for numerical modelling

The study specializes in the area of mechanical properties of select fibre reinforcement concrete. For the research fibre concrete reinforced with short steel fibres was used without bending. Fibre concrete is produced in the dosing 40 and 75 kg/m3. Laboratory program includes a complete group of tests, i.e. concrete compressive strength in cubes, three-point bending test, and split tension strength perpendicular and parallel to filling direction. Results are processed in summary, and they also include fracture-mechanical parameters needed for structural modelling. The research carried out found the positive influence of fibre on tensile strength and fracture energy. However, with more fibre, only fracture energy increases. It has also been found that the effect on compressive strength is small. For numerical modelling, the suitability of using a 3D computational model in combination with the fracture-plastic material model for fibre reinforcement concrete was verified.

KORELASI NILAI KOEFISIEN ARAH SERAT BETON TERHADAP KEKUATAN TARIK LENTUR PADA BETON DENGAN SERUTAN BAJA MAUPUN HAREX SF

Concrete has high compressive strength that is capable of supporting a large and heavy structures. But concrete has a low tension strength and brittle nature (Brittle). The weakness of this concrete properties can be improved by providing treatment such as provide fiber. There are several fibers that can be used to improve the properties of concrete and one of them is the steel fibers. Steel fibers possess the strength and modulus of elasticity which is relatively high. Moreover steel fibers do not change the shape of the influence of alkali in the cement. Imposition in a long period o f time does not affect the mechanical properties of steel fiber. Bond in the composition of the mixture can be increased because fastening mechanically. The study used the steel shavings and fiber materials Harex SF. The aim of this examination was intended to determine the coefficient of concrete fiber orientation at the same time the value of flexural tension strength of concrete produced in the concrete mix wearing Harex SF fiber or steel shavings. Steel fiber used in this study using the percentage of 1 until 4 percent of the weight of the concrete mix and perform quality control for the split tension strength of concrete at 28 days. From this research, the percentage of 3 percent as the optimum value based on the ease of doing the concrete (workability) used for research flexural tension strength of concrete and fiber orientation coefficient of concrete in the concrete with steel shavings and concrete with fibers Harex SF. From the testing that has been done shows: flexural tension strength fiber-reinforced concrete Harex SF 3 percent of 5,037 MPa and flexural tension strength of concrete with steel shavings of 11,035 MPa and the coefficient offiber direction concrete well with fiber Harex SF and shavings o f steel both are between 0 and 1 (0 less than or equal to eta of phi less than or equal to 1) with an average value close to 0, which means both fibers are working properly so that is proven to increase the tension strength offlexural concrete.

Influence of duration of heat curing and extra rest period after heat curing on the strength and transport characteristic of alkali activated class F fly ash geopolymer mortar

In the study, the influence of heat curing duration and rest period after heat curing duration on the strength and transport characteristics of alkali activated fly ash (AAFA) mortar were investigated. A local class F type fly ash, CEN reference sand, sodium hydroxide and potable water were used in preparation of cement-less fresh geopolymer mortar mixture. Mixture ratios (in mass basis) were 3, 1, 0.29, and 0.1 for sand, fly ash, water and sodium hydroxide, respectively. Some samples were cured at 75°C temperature for 4h, 1, 2, 3 and 7days; then, they were tested after heat curing period. Additionally, some of the equivalent samples were kept in the laboratory at 23±2°C temperature with 50±5% relative humidity, until 28days after their initial heat curing period. Then, they were tested at 28days for combined curing conditions. The measured properties of AAFA mortar were unit weight, porosity, capillary water absorption, water absorption capacity, flexural-bending and split tension strength, compressive strengths and abrasion resistance. It was observed that the strengths of mortar were significantly increased with the increase in heat curing duration. A significant strength development was also observed after rest period. As a result of the study, high strength and abrasion resistant AAFA geopolymer mortar was produced. However, transport properties of AAFA geopolymer mortar found to be not as good as mechanical properties.

An Orthogonal Test of Steel-polypropylene Hybrid Fiber Lightweight Aggregate Concrete

Using orthogonal test, cubic anti-pressure test and splitting tension strength test were carried out on 9 groups of steel-polypropylene (PP) hybrid fiber lightweight aggregate concrete and 1 group of standard lightweight aggregate concrete, in order to explore the impacts of steel fiber content, length-diameter ratio of PP, and PP content on light aggregate concrete's mechanical performance. Based on the test results, an optimum mix ratio of steel- PP hybrid fiber lightweight aggregate concrete has been found.

Strength and micro-structure evolution of compacted soils modified by admixtures of cement and metakaolin

Metakaolin, widely applied in concretes and cement-stabilized soft clays to improve their macro performance, was evaluated for use in compacted soils in highway and backfill engineering. The compactability and strength performance of cement-modified soils with metakaolin were evaluated in the terms of their applicability and effectiveness. The cement-based modified soil with metakaolin was more insensitive to water and more convenient in the field rolling compaction. The strengths, in addition to the unconfined compressive strength and splitting tension strength, were improved significantly. Up to a threshold ratio of metakaolin to cement ranging from 1/3 to 1/2 in this case, the strengths increased gradually, while they unexpectedly decreased thereafter. This phenomenon was different from the previously reported metakaolin applications in concrete and cement-stabilized soft clays, which was probably due to the water content and the ratio of metakaolin to hydrated calcium hydroxides of the cements. Microstructure analysis by X-ray diffraction, scanning electronic microscopy, thermo-gravimetric analysis and mercury intrusion porosimetry, demonstrated that the addition of metakaolin led to a higher quantity of hydration products and a denser micro-porosity distribution.

EFFECTS OF REPLACEMENT OF METAKAOLIN WITH CEMENT ON THE MECHANICAL PROPERTIES OF SIFCON

Slurry Infiltrated Fibrous CONcrete (SIFCON) is unique type of concrete invented by Lankard in 1979, containing high percentage of fiber about 6% to 20% by volume of concrete. SIFCON possesses high strength as well as large ductility and for excellent potential for structural application. Metakaolin (MK) is a pozzolanic material, which improves the durabilityand strength of concrete. In this study the test programs were carried out with 2%, 3% and 4% of fiber content by volume of concrete with replacement of cement by Metakaolin at 5% and 7.5% by weight of cement. The aim of work is to optimize the percentage of fiber content and to minimize the cement usage by replacing it by Metakaolin. It also gives way to effective disposal of industrial waste to avoid global problem and protect environment. The main objective of this work was to determine the effect of replacement of cement with Metakaolin on mechanical property of SIFCON mortar. For that purpose compressive strength, flexural strength and Split tension strength of SIFCON specimen were tested after 7 and 28 days of curing, yielding positive results. In this study, we found that 2% fiber replacement by volume of concrete and Metakaolin at7.5% by weight of cement yields best and economical results.

An Experimental Study of the Dynamic Split Tension Properties of Reinforced Concrete

Dynamic split tensile tests of reinforced concrete were carried out using the split Hopkinson pressure bar experimental technique to determine the failure modes of reinforced concrete at different strain rates, and the effect of reinforcement ratio and reinforcement layouts on the dynamic performance. The specimens with nine reinforcement ratios were used in the tests. Experimental results show that the tensile strength of reinforced concrete exhibits a critical strain rate, beyond which a larger increase in dynamic strength of specimens occur. The dynamic split tension strength of reinforced concrete is demonstrated to be greater than the plain concrete with the same strength grade over the range of tested strain rates. The results also indicate that the dynamic split tension strength of specimens enhances with the increase in the reinforcement ratio. These findings are instrumental to guide the structural design of reinforced concrete in engineering applications.

Effects of rubber particles on mechanical properties of lightweight aggregate concrete

This paper presents the compiled experimental data of slump value, compressive strength, splitting tension strength, flexural strength, static modulus of elasticity and unit weight for eleven different mixtures of rubber lightweight aggregate concretes cured up to 1, 7 and 28days. The eleven different mixtures cover one fundamental mixture and ten different replacements of rubber particles for sand volume from 10% to 100%. Based on the experimental results, incorporating rubber particles profoundly has a detrimental effect on the slump and mechanical strength, while the unit weight of concrete dropped. The static modulus of elasticity decreased from 24.1GPa to 6.3GPa with the replacement of rubber particles increasing from 0% to 100%. The toughness of rubber lightweight aggregate concretes is obvious superior to the plain lightweight aggregate concretes. The application of rubber particles in lightweight aggregate concretes provides further opportunity to recycle waste tires.

Strength Properties of Recycled Aggregate Concrete Mixed with Polypropylene Fiber

This research is to verify and propose the practical use of recycled aggregate concrete which is one of the recycling methods of construction wastes. This is because domestic construction industries have been more sustainably developed, and renovation and redevelopment of buildings for increasing the quality of life have been actively performed because the necessity of efficient management of construction wastes has been increased. In addition, the possibility of increased quality focused on recycled aggregate concrete with mixed polypropylene fiber was proposed on this research through material experiments basedon compressive and split tension strength.

Experiments for Strength Properties of Polypropylene Fiber-Reinforced Concrete

This paper made experimental research on the compressive strength, axis compressive strength and splitting tension strength of polypropylene fiber-reinforced concretes at a fiber content of 0.9Kg/m3 in different ages which showed that: in the experiment of compressive strength, the strengths of C20 polypropylene fiber concretes in the ages was lower; the strength of C30 polypropylene fiber concretes in the age of 7 days was lower, the strengths in the ages of 14 days and 28 days were basically equal to; the strength of C40 polypropylene fiber concretes in the age of 7 days was basically equal to and in 28 days was higher than the strengths of ordinary concretes. In the experiment of axis compressive strength, the strengths of C20 polypropylene fiber concretes in the ages were lower; the strengths of C30 polypropylene fiber concretes in the age of 7 days and 14 days were lower and in the age of 28 days was basically equal to; the strengths of C40 polypropylene fiber concretes in the ages were basically equal to the strengths of ordinary concretes. In the experiment of splitting tension strength, the strengths of C20 and C30 polypropylene fiber concretes were lower; the strength of C40 polypropylene fiber concretes in the age of 28 days was basically equal to the strengths of ordinary concretes. Conclusion: the relationships between the strength of fiber concretes and ordinary concretes are correlated to the strength grades of concretes, namely, When the strength degrade of concretes is low, the strength of polypropylene fiber concretes is lower, but the strength reaches closer to or exceeds the strength of ordinary concretes along with the increase of the strength grade of concretes.

Study on Pavement Performance of Reclaimed Asphalt Mixture

In order to improve the pavement performance of reclaimed asphalt mixture, using Marshall test, rutting test, splitting test and long-term aging test, taking stability, dynamic stability, fatigue strength, stiffness modulus, and freeze-thaw splitting tension strength as the target, the influence law of old asphalt mixture content and regenerant content on pavement performance of reclaimed asphalt mixture is systematically studied. The results show that: the proportion of old asphalt mixture has no influence on high temperature performance of reclaimed asphalt mixture. With the proportion of old mixture increases, the optimum asphalt-aggregate ratio, low temperature performance, water stability, and anti-aging property of reclaimed asphalt mixture decrease. Addition of regenerant improves the low temperature performance of reclaimed asphalt mixture, and reduces the strength and high temperature stability of reclaimed asphalt mixture. Research results have great guiding significance for old asphalt mixture content selection, regenerant content selection and improving pavement performance of reclaimed asphalt mixture.

Effect of Autoclaved Aggregate Structure on Strength of Concrete

This paper focuses on studying the physical and mechanical performance of propylene oxide sludge aggregates having no shell (POSA-0), single storey shell (POSA-1) and gradient shell (POSA-2) prepared by hydrothermal synthesis and autoclave curing process. The effect of the aggregate structure on strength of their concrete has been examined and discussed in case of a fixed water cement ratio. The results show that all the autoclaved propylene oxide sludge aggregate (POSA) were light-weight and high-strength regardless of the aggregate structure and all three structured POSA have no wall effect with the cement mortar. Aggregate structure has little influence on the physical and mechanical performance of POSA and splitting tension strength of POSA concrete, however, it plays important role in dictating the compressive strength of concrete because of their different extent of influence on the improvement of interface and relieving the stress concentration. 28d compressive strength of the concrete with the POSA-2 as coarse aggregate can reach 82 MPa, which is 13.9%, 2.5% and 10.8% higher than that of the concrete with POSA-0 as coarse aggregate, the concrete with POSA-1 as coarse aggregate and common concrete, respectively. 28d splitting tension strength of common concrete can reach 7.76 MPa, which is higher 22.6%, 16.3%, 15.8% than that of concrete with POSA-0 as coarse aggregate, concrete with POSA-1 as coarse aggregate and concrete with POSA-2 as coarse aggregate, respectively.

A preliminary concrete mix design for SCC with marble powders

The marble has been commonly used as a building material since ancient times. Disposal of the waste materials of the marble industry, consisting of very fine powders, is one of the environmental problems worldwide today. However, these waste materials can be successfully and economically utilized to improve some properties of fresh and hardened self-compacting concrete (SCC). The aim of this study is to find some relationship between properties of the fresh SCC and the hardened SCC containing marble powder. For this purpose, the mix design approach based on monogram developed by Monteiro and co-workers for normal vibrated concrete was adapted to SCC mixes. In order to obtain this monogram, a series of SCC mixes with different water/cement ratios and water/powder ratios were prepared. Several tests such as slump-flow, T 500 time, L-box, V-funnel and sieve segregation resistance were applied for fresh concrete and tests such as compressive strength and split-tension strength at 7, 28 and 90 days were performed for hardened concrete. In conclusion, the mix design method based on monogram can be suggested for preliminary design in SCC.