Mechanical Properties Of Pervious Concrete Research Articles

Assessing the impact of recycled concrete aggregates and metakaolin on the mechanical properties of pervious concrete

Population growth and urban expansion have increased impervious surfaces, leading to environmental issues such as stormwater runoff and groundwater depletion. Traditional concrete, while durable, contributes to these problems. There is a need for sustainable construction materials that can address environmental challenges and reduce the consumption of natural resources. Pervious concrete, enhanced with recycled aggregates (RCA) and supplementary cementitious materials (SCMs) like metakaolin (MK) present a potential solution. This study aims to improve the mechanical and durability properties of pervious concrete by incorporating RCA and MK, assessing their effects on workability, density, porosity, permeability, compressive strength and flexural strength. The incorporation of RCA resulted in increased aggregate porosity compared to natural aggregates. Workability was assessed using the slump test, density was measured, and porosity and permeability were evaluated. The results showed that incorporation of RCA generally decreased workability, density and strength, while the addition of MK improved these properties by refining the microstructure. Specifically, mixes with 10% MK demonstrated better performance in terms of increased compressive and flexural strengths, improved density and reduced porosity. The ANN model showed high accuracy in predicting compressive and flexural strengths. The study concludes that RCA and MK can enhance the mechanical and durability properties of pervious concrete.

Influence of aggregate size on pervious concrete properties with and without construction and demolition waste

This research evaluates the impact of aggregate sizes on pervious concrete properties, comparing aggregates of 12.5 mm and 19 mm, as well as replacing natural aggregates with recycled aggregates set at 0% and 50%. Four types of pervious concrete were produced, and their properties were determined: density, porosity, permeability coefficient, compressive strength, flexural tensile strength, and abrasion resistance. The results indicate that water permeability is directly related to pore size and is influenced by aggregate size (90% of the variation in pervious concrete permeability) and, to a lesser extent, by recycled aggregate content (10% of the variation). Mixes with larger aggregates (19 mm) demonstrated higher permeability coefficients. Replacing natural aggregates with recycled aggregate did not significantly affect the mechanical properties of pervious concrete, highlighting the effectiveness of waste processing and mixing procedures, allowing for the incorporation of 50% of recycled aggregate. The concretes met the requirements of the American Concrete Institute, suggesting technically feasible conditions for sustainable practices in the construction industry.

Current research status and application prospects of permeability and mechanical properties of pervious concrete

Permeable concrete, characterized by continuous porosity, offers excellent properties such as breathability, water permeability, sound absorption, water purification, and environmental enhancement. This paper comprehensively reviews previous research on permeable concrete, encompassing studies on mix design, workability, mechanical properties, drainage performance, sound absorption, and durability. It also discusses improvement measures and application prospects. Research indicates that the performance of permeable concrete is influenced by factors such as mix design, material composition, and construction techniques. Optimizing mix design, modifying material composition, and enhancing workability and mechanical properties can further improve the performance of permeable concrete. Permeable concrete shows broad application prospects in road engineering, landscaping, and environmental engineering, but further research and standardization are needed to support its widespread adoption.

EXPERIMENTAL INVESTIGATION AND INTELLIGENT PREDICTION OF MECHANICAL STRENGTH OF PERVIOUS CONCRETE

This study determines the mechanical strength characteristics of pervious concrete using fuzzy logic. During construction, the process of determining the quality of concrete produced takes about 28 days before testing, training the fuzzy logic model through the research data gotten from the laboratory experiments in order to intelligently predict the mechanical strength of pervious concrete. Crushed granite was used in this experiment to ensure the pervious concrete has a little degree of fine aggregates and the maximum size of coarse aggregate used was 20 mm. Compressive, flexural and split tensile strength tests were carried out on pervious concrete of mixing ratios 1:4, 1:5 and 1:6 with each of the mixing ratios having varying water to cement ratios of 0.4, 0.5, 0.6 and 0.7. The developed fuzzy logic model was applied to predict the mechanical strengths of the concrete by using data obtained from experimental results, with input parameters of water content, crushing value, weight and density and the mechanical strengths as the output parameters employing the triangular membership function. The model was calibrated using the error measures of the root mean square error (RMSE), mean absolute percentage error (MAPE) and R squared were computed for the model. In this study, it was observed that higher water to cement ratio slightly reduces the mechanical strength of PC but increases the workability compared to increase in cement to granite ratio which notably increases the strength and reduced the workability, alternatively, higher water to cement ratio causes a notable decrease in permeability of the pervious concrete. The correlation between the experimental and predicted values was excellent. This shows that fuzzy logic can be used to predict the mechanical properties of pervious concrete, and fuzzy logic can also be used to appropriately deduce missing values in the mechanical properties of PC subject to further research

Influence of freeze–thaw cycles on mechanical properties of pervious concrete: From experimental studies to discrete element simulations

In this paper, pervious concrete (PC) was prepared using fly ash, granulated blast furnace slag, and rice husk ash as supplementary cementitious materials (SCMs), and the mechanical properties, water permeability, and freeze–thaw durability of permeable concrete were mainly investigated. Discrete elements (DEM) were used to mimic the freeze–thaw cycle process of pervious concrete to assess better how freeze–thaw cycles affect the mechanical properties of pervious concrete. To allow water particles of various sizes to fill the model pores, new algorithms were developed. However, since some connected pores release some of the pressure generated by water expansion when undergoing FTCs, two different water particles must be defined. Meanwhile, an elastoplastic parallel bond contact model (EPPBM) was created to account for any residual strain brought on by water freeze–thaw expansion at the aggregate bond. Through experiments, it was determined that adding SCMs increased the compressive strength of the pervious concrete by 1.22 %, 15.32 %, 32.34 %, and 35.20 % at 7, 28, 56, and 90 days compared to the control group. The microstructure of the hydrated calcium silicate (C-S-H) gel could be relatively dense by SEM. The width of the interfacial transition zone (ITZ) was found to have been effectively shortened by further scanning using EDS. As a result, in the tests of mechanical properties after freeze–thaw cycles (25, 50, 75, and 100 cycles), there was a significant improvement in the loss of strength compared to the control group, which was 2.13 %, 6.91 %, 10.04 %, and 17.40 %, respectively. Using numerical simulation to correct the functional correlation between FTCs and the mechanical characteristics of permeable concrete, the trend essentially aligns with the experiment's results, demonstrating the model's viability. Acoustic emission monitoring of model rupture location and strain energy loss after FTCs were utilized and the effect of different porosity and initial uniaxial compressive strength (UCS) on the attenuation constant of the freeze–thaw resistance of pervious concrete was analyzed. The decay constant of UCS increased with increasing porosity and elastic modulus while decreasing with increasing initial UCS. Therefore, the decay constant of UCS and elastic modulus after arbitrary FTCs can be easily estimated using the initial parameters of the pervious concrete.

Study of the Mechanical and Physical Properties of Pervious Concrete Modified with Treated and Untreated Natural Coconut Fiber for Pavement

Pervious concrete pavements (PCP) are a novel material that numerous researchers are studying and focusing on. Its inexpensive cost, quick construction, and simple implementation are gaining favour. The aim of this study is to investigate the mechanical properties of pervious concrete pavement as well as the effects of modifying it with natural fibres such as coconut fibre. In this study, two types of coconut fibre were used: untreated (raw) fibre and alkali-treated fibre, as well as aggregates of various grades. By varying the amount of coconut fibre added by volume fractions of 3%, 6%, and 9%, the PCP mixes were generated. The fibre was treated with sodium hydroxide (NaOH) and is 2.5–3.5 cm long. The results showed that a 3% addition of treated natural fibre improved the mechanical properties of the PCP. Natural coconut fibre is able to be used as a concrete modification to improve its flexural behaviour and strength. According to the findings of this study, using 3% coconut fibre in the mix design of PCP at the age of 28 days improves tensile strength by 1.3 MPa, compressive strength by 4.8 MPa, and flexural strength by 1.92 MPa, whereas using 6% and higher fibres decreases flexural and split tensile and compressive strengths.

Effect of fly ash addition on the mechanical properties of pervious concrete

Due to the unique permeable characteristics, the use of pervious concrete finds applications in various construction projects. The perviousness of the concrete can be achieved through exclusion of fine aggregates from its matrix. The study investigates the possibility of developing a sustainable pervious concrete through the utilization of fly ash as a partial replacement for cement. The overall objective of the current study is to promote sustainability in the development of a pervious concrete by partial replacement of cement by fly ash without compromising the strength. In total, different trails were prepared by replacing the cement with fly ash up to 40% in levels of 10%. Two sizes of coarse aggregates such as 12.5 mm and 20 mm were added to identify their significance. The experimental findings revealed that the mechanical properties of pervious concrete were improved with 20% of fly ash. After 28 days of curing, addition of higher proportion of fly-ash resulted in the decrease of compressive strength. Another important observation is the downfall of the porosity (i.e., high permeability) due to the increasing dosage of fly-ash.

Influence of the Addition of Recycled Aggregates and Polymer Fibers on the Properties of Pervious Concrete.

The aim of the study was to check the possibility of reusing aggregate from recycled concrete waste and rubber granules from car tires as partial substitution of natural aggregate. The main objective was to investigate the effects of recycled waste aggregate modified with polymer fibers on the compressive and flexural strength, modulus of elasticity and permeability of pervious concrete. Fibers with a multifilament structure and length of 54 mm were deliberately used to strengthen the joints among grains (max size 31.5 mm). Eight batches of designed mixes were used in the production of pervious concrete at fixed water/binder ratio of 0.34 with cement content of 350 kg/m3. Results showed that the use of recycled concrete aggregate (8/31.5 mm) with replacement ratio of 50% (by weight of aggregate) improved the mechanical properties of pervious concrete in all analyzed cases. Whereas the replacement of 10% rubber waste aggregate (2/5 mm) by volume of aggregate reduced the compressive strength by a maximum of 11.4%. Addition of 2 kg/m3 of polymer fibers proved the strengthening effect of concrete structure, enhancing the compressive and tensile strengths by a maximum of 23.4% and 25.0%, respectively. The obtained test results demonstrate the possibility of using the recycled waste aggregates in decarbonization process of pervious concrete production, but further laboratory and field performance tests are needed.

Influence of Calcined Clay Pozzolan and Aggregate Size on the Mechanical and Durability Properties of Pervious Concrete

Pervious concrete has been reported as a viable solution to reduce stormwater run-off, the heat-island effect, road noise, and pavement flooding. Previous researchers have focused on analysing the structural properties and functionality of pervious concrete. However, relatively few studies have been conducted into the addition of supplementary cementitious materials (SCMs), such as calcined clay, in pervious concrete and its effect on long-term durability. This paper has studied the effect of calcined clay pozzolan as a partial substitute for Portland cement in pervious concrete, together with the influence of coarse aggregate size. A water–binder ratio of 0.4 and aggregate–binder ratio of 4.0, as well as a superplasticiser content of 0.95%, were maintained for all mixes. Two sizes of coarse aggregates were used for this study: 9.5 mm and 20 mm. CEM-I cement was partly substituted with calcined clay in dosages of 0 to 30% in replacement intervals of 5%. The mechanical tests conducted included the split tensile test, compressive strength test, and flexural strength test. Durability measurements such as the rapid chloride permeability test (RCPT), thermal conductivity and sulphate resistance tests were also carried out. The mechanical properties of the pervious concrete followed a similar trend. The results showed that at 20% replacement with calcined clay, the compressive strength increased by 12.7% and 16% for 9.5 mm and 20 mm aggregates, respectively. The flexural strength improved by 13.5% and 11.5%, whereas the splitting tensile strength increased by 35.4% and 35.7%, respectively, as compared to the reference concrete. Beyond 20% replacement, the tested strengths declined. The optimum calcined clay replacement was found to be 20% by weight. Generally, pervious concrete prepared with 9.5 mm obtained improved mechanical and durability properties, as compared to those of 20 mm aggregates.

Experimental study on size of aggregates, size and shape of specimens on strength characteristics of pervious concrete

Pervious concrete has a wide range of applications including pervious pavements, rigid drainage layers and water-free floor. In this paper, the influence of aggregate size, shape, and size of specimens on the mechanical properties of pervious concrete has been investigated. Tests on pervious concrete include direct compression on cubes and cylinders, splitting tension, and flexural tests on respective cylinders and prisms were carried out on three different mixes with aggregate sizes of 10, 12.5, and 20 mm. The height of specimens was kept as the primary variable whereas the aspect ratio was kept constant. Experimental results indicated that when aggregate size and height of specimen increases, compressive, splitting tensile and flexural strength decreases. Using Size effect models such as Linear model, Bažant's Size Effect Law and Modified Size Effect law, an approach is proposed to predict non-standard specimen strength from known standard specimen strength with high accuracy.

Reuse of waste rubber in pervious concrete: Experiment and DEM simulation

The reuse of waste rubber has a profound impact on environmental protection and resource recycling. To evaluate the feasibility of adding waste rubber into pervious concrete, the effects of rubber content and particle size on the mechanical properties of pervious concrete are investigated through experiments and discrete element method (DEM) simulation. The compressive failure mode of pervious concrete gradually transits from tensile failure to shear failure with the increase of rubber content, showing a decrease in compressive strength, and the larger the particle size is, the stronger the attenuation effect on the strength is. Rubber particles play a role in isolating coarse aggregates from the cement matrix and form a weak bond with the matrix, showing a weak bridging effect in stress transmission at the left and right ends of the crack, so that the splitting tensile strength of pervious concrete significantly decreases with the increase of rubber content, and the weakening effect of coarse rubber on the splitting tensile strength is stronger than that of fine rubber. Due to the low strength of rubber itself and weak bonding with cement matrix, pervious concrete with high rubber content breaks in advance at the bottom of the midspan, resulting in the decline of flexural capacity, and it decreases more obviously with the increase of rubber size. Although the direct tensile strength of pervious concrete gradually decreases with the increase of rubber content, the addition of rubber improves the plasticity of pervious concrete. Moreover, the plastic reinforcement effect of pervious concrete is the strongest when the rubber content reaches approximately 10%, and this toughening effect increases with the decrease of rubber size. On the basis of experimental research, a universal DEM model considering rubber content and particle size is established, which can well predict the mechanical performance of rubberized pervious concrete in terms of strength, failure mode, elastic modulus and ultimate strain.

Effect of silica fume on the physical, hydrological and mechanical properties of pervious concrete

Pervious concrete is a special concrete which is prepared by partial or complete elimination of fine aggregates. Thus, the quality of the cement paste plays a crucial role in defining the properties of pervious concrete. This study aims at investigating the impact of replacing cement in pervious concrete by silica fume. Cement in pervious mix was replaced partially by silica fume in a range of 0 to 20% at 5% intervals. Two varying sizes of aggregates namely 12.5 mm and 20 mm (single-sized) were used in mixes and the aggregate to cementitious material ratio was maintained at 3.54 with a water cement to cementitious material ratio of 0.35. The investigated properties include density, porosity, permeability, abrasion resistance and mechanical properties namely compressive strength, tensile strength and flexural strength. Incorporation of silica fume up to 15% was found to cause considerable positive impact on the mechanical properties of pervious concrete irrespective of the aggregate size due to their pozzolanic behavior which improved the paste formation. The compressive strength, split tensile strength and flexural strength were increased to a maximum of 20.14%, 12.73% and 13.74% respectively with the use of 12.5 mm aggregates and 15% of silica fume. The output of the experiments revealed that the cement content of the pervious mix can be optimally replaced up to 15% with silica fume for balanced physical, hydrological and mechanical properties.

Performance Simulation of Permeable Concrete Materials Combined with Nanotechnology in Rainwater Management

In recent years, China has entered a period of rapid urban development, but most of the cities with rapid development still have ground hardening, which makes it difficult for rainwater to penetrate and discharge. In order to achieve the rapid drainage of accumulated water in the city, nanotechnology was introduced, and permeable concrete based on NC and NS nanomaterials was proposed. Combined with finite element analysis, the permeable properties and mechanical properties of permeable concrete mixed with nanomaterials were analyzed. A comprehensive performance analysis of pervious concrete shows that the viscosity of permeable concrete mixed with nanomaterials is significantly higher than that of non-mixed pervious concrete, and the permeability coefficient of permeable concrete mixed with nanomaterials can reach 0.43 cm/s. A finite element analysis shows that the incorporation of nanomaterials can improve the compressive strength of permeable concrete. At the same time, under a rainwater environment simulation, the rainwater retention time of pervious concrete is only 2.35 s. The above results show that the incorporation of nanomaterials into pervious concrete can improve the water permeability of pervious concrete, improve the mechanical properties of pervious concrete, and increase its service life, which is of great significance to urban development and urban management.

Mechanical and Hygrothermal Properties of Zeolite-Modified Pervious Concrete in Hot and Humid Area

Pervious concrete has good permeability and moisture adjustment properties due to its rich pore structure. It can not only reduce surface runoff by infiltration of rainfall, but also retain a certain amount of water inside, and then decrease the surface temperature via evaporation. In order to optimize the evaporative cooling performance of pervious concrete, this study introduces a modified method of incorporating superabsorbent zeolite produced from industrial wastes into pervious concrete as hygroscopic filler. The effects of zeolite dosages on the basic physical and mechanical properties of pervious concrete were analyzed, and then the evaporative cooling performance of zeolite-modified pervious concrete with the optimum replacement rate was studied. The results showed that the zeolite addition significantly reduced the density of pervious concrete, while having little impact on the permeability. The compressive and splitting tensile strength of pervious concrete increased first and then decreased as the replacement rate of zeolite powder increased, and the content of 15% zeolite powder and 20% zeolite aggregate was beneficial to improve the mechanical properties of pervious concrete. Contributing to the abundant micro-pores and higher specific surface area of zeolite particles, this could improve capillary water absorption and the water storage ability of pervious concrete. During the process of evaporation, the water absorption increment could effectively reduce the surface temperature by 5–8 °C, and maintain the evaporation cooling effect for 10–12 h.

A Laboratory Study of Mechanical Properties of Pervious Concrete as A Pavement Material by Partial Replacement of GGBS in Cement with Addition of Cellulose Fibers

Abstract: Among all the transportation systems roadways is most typically used transportation system. but in present scenario roads faces plenty of issues like potholes, cracks and plenty of other distresses. Not even these however water is additionally the main enemy to the pavement that causes deformations and changes the feel of subgrade soil leading to giant variation in performance. The total impervious Surface amendment (ISC) for Asian nation between 2000 and 2010 is 2274.62 km2 . This is one of the foremost significant issues thanks to speedy urbanization wherever there's a tremendous increase in construction of black topped and differing kinds of impervious pavements. This has associate adverse result on the setting because the storm water becomes stagnant over the surface of the pavement thanks to inadequate emptying conditions. The necessity for reducing stagnation and therefore the surface runoff has given the origination of pervious pavements surface. pervious concrete pavement may be a special style of its kind with high consistence with no or borderline fines which permit water to percolate through it and therefore the water that is accumulated over the surface ought to be collected and might be used for numerous purposes and basic wants. The present work studied the mechanical properties, sturdiness and permeability of pervious concrete of combine 1:3 mixture cement magnitude relation. The management combine is altered by partially replacing 30% of cement with Ground Granulated Blast furnace slag (GGBS), enclosed cellulose fibres of fifty of weight of the building material material and combination of each in one combine and compared the results obtained. The properties like compressive strength, porousness, indirect strength, flexural strength, are assessed by acting tests. it absolutely was discovered that there's a rise in Compressive Strength, Split strength, Flexure Strength and reduce within the permeability within the altered pervious concrete mixes when put next to the pervious concrete with no additives

Characterization of PVA Fiber-Reinforced Pervious Concrete with Blended Recycled Ceramic Aggregates and Natural Aggregate

Effective industrial waste management is one of the important challenges facing modern society. Ceramic wastes occupy an important proportion of industrial waste. The utilization of waste of ceramics is becoming more and more attractive for many researchers to alleviate the environmental impact of industrial waste. As a low-impact development method, pervious concrete (PC) received more and more attention from researchers in recent years. However, the relatively low strength compared with ordinary concrete restricts the application of pervious concrete. This research used recycled ceramic coarse aggregates (RCCA) to partially replace natural coarse aggregates (NCA) to prepare recycled ceramic coarse aggregate pervious concrete (RCCAPC) and fiber-reinforced RCCAPC incorporating polyvinyl alcohol (PVA) fibers, and the effect of the replacement rate of RCCA and the amount of PVA fiber on the mechanical properties and permeability was investigated. The results show that RCCA can improve the mechanical properties of PC at a low substitution rate, as well as PVA fiber, and when the PVA content is about 0.3%, the enhancement effect is the best. Both RCCA replacement rate and PVA fiber content have little effect on the permeability coefficient of PC. Based on described studies, using RCCA to partially replace NCA at a low substitution rate is suitable for the preparation of PC, and PVA fibers can enhance the strength of PC, which may help to broaden the application scenarios of PC.

Experimental Investigation on Influence of Molding Methods on Properties of Pervious Concrete

Despite the common use of pervious concrete (PC), there is no standard way of producing the test specimens, which undergo testing to infer the behaviour of PC in the field. Vibrating table is the most common method but greatly reduced in vibration time compare with normal concrete in the laboratory. Marshall compaction and superpave gyratory compactor (SGC) are recommended standard molding methods for porous asphalt mixtures manufactured in the laboratory environment. Three kinds of pervious concrete samples with three target porosities were prepared by the above three methods, and the effects of the molding method on the physical properties, mechanical properties and durability of the samples were investigated in the study. Experimental results showed, with different molding methods adopting, pervious concrete with the same mixture design exhibits slightly different physical and mechanical properties. After analysis and comparison, SGC is the best choice to obtain concrete with high permeability, good freeze-thaw resistance and high strength, followed by Marshall compaction molding, and vibration molding is the last one. As a result, a win-win situation of the hydraulic characteristics and mechanical properties of pervious concrete can be achieved due to both optimized mix-design and appropriate molding method.

Experimental Study on Mechanical Properties of Pervious Concrete Containing Recycled Aggregate

This investigational study aims to examine the influence of using recycled coarse aggregate (RCA) instead of natural coarse aggregate (NCA) on the fresh properties (workability) and mechanical properties of pervious concrete (PC). The mechanical properties include compressive strength, splitting tensile strength and flexural strength and the impact resistance of PC was also assessed using drop weight test. In total, four mixes were prepared (including control mix with 100% NCA) in which various ratios of RCA (30%, 70% and 100%) replaced the NCA in the preparation of PC mixes without using any fine aggregate and fixing the water-cement ratio (w/c) to 0.4. The outcomes of the study reveal that the content of the RCA has significant adverse effects on the workability and mechanical performance of the investigated mixtures. This adverse effects increase with the increase of the content of RCA. The strength reduction, compared to the mix with NCA, reached to 59% for compressive, 28% of the splitting tensile, 38% for flexural strength and 50% for the impact resistance when 100% RCA is used.

Effect of Different Mineral Admixtures on the Properties of Pervious Concrete

Taking pervious concrete with a target porosity of 15% as the research object, the influence of three factors, including the contents of silica fume (mass fraction3%, 5%, 7%), metakaolin (mass fraction8%, 10%, 12%) and Polypropylene fiber content (volume fraction1%, 2%, 3%), on the mechanical properties, permeability and frost durability of pervious concrete were investigated by utilizing the orthogonal testing method. Through the range analysis of the test results, the significant influence degree of the three factors were obtained, and the freeze-thaw cycle test was carried out with the optimal mix ratio. The results indicated that the content of silica fume and metakaolin has the most significant influence on the mechanical properties of pervious concrete, the fiber has the most significant influence on the continuous porosity, but the influence on the compressive strength is small. The best mix proportion was obtained, and the silica fume content is 7%, metakaolin content is 10%, and fiber content is 2%. The results of freeze-thaw cycle test of pervious concrete with optimal mix ratio show that the relative dynamic modulus and compressive strength of pervious concrete decrease gradually with the increase of freezing-thawing cycles, and the change rate of mass loss, continuous porosity increases gradually with the increase of freeze-thaw cycles. The relative residual compressive strength and dynamic elastic modulus of pervious concrete show a parabolic decline trend subjected to freeze-thaw cycles. The results also can provide technical reference for the engineering application of pervious concrete in cold regions.

Enhancing the mechanical properties of pervious recycled aggregate concrete using silicafumes

The growth of construction industry in India is increasing enormously over the last few years. This demands a huge quantity of construction materials across the globe which indirectly has a serious impact on the environment that includes aggregate scarcity, inadequate ground water recharge due to impermeable paved surfaces, dust and noise pollution. The use of recycled concrete aggregate in construction industry will mitigate the impact to some extent and also the construction of permeable surface helps in ground water recharge. In this study, the effect of recycled concrete aggregate on mechanical properties of pervious concrete is studied. In addition, the strength of pervious concrete composed of recycled concrete aggregate is enhanced by the addition of silicafumes from 8% to 16% in increments of 2%. The effect of silica fume on permeability and flexural strength is also studied.