Experimental Investigation on Bacterial Concrete with Micronized Biomass Silica

Million loads of coal wastes are being generated everywhere across the globe in the form of fly ash and bottom ash. Utilization of such waste materials in concrete is an eco-friendly choice. Therefore, the objective of the current experimental investigation is to explore the effects of fly ash and bottom ash on the properties of concrete by replacing them partially with natural fine aggregate and cement, respectively, on an individual basis as well as on combined basis. Concrete specimens are prepared by replacing 0%, 20%, 30%, 40% and 50% of sand by coal bottom ash and 0%, 20%, 30%, 40% and 50% cement by coal fly ash. Thereafter, the concrete specimens are prepared by replacing optimum percentages of both cement and sand by coal fly ash and coal bottom ash, respectively. The compressive strength, split tensile strength, flexural strength and density of the above mixes are obtained from the experimental investigation. From these results, it is found that for concrete mix with 20% coal fly ash and 30% coal bottom ash, the compressive, split tensile and flexural strength reduce by 10.5%, 10.7% and 9.6%, respectively, with reference to those of the control mix. Moreover, for the above concrete mix, the dry density also reduces by 10.3% from the control mix. These properties of the concrete mix with 20% coal fly ash and 30% coal bottom ash are further improved by adding a suitable dose of superplasticizer.

A study on mechanical properties of rubberised concrete containing burnt clay powder

The focus of this research is to isolating and identifying bacteria that produce calcite precipitate, as well as determining whether or not these bacteria are suitable for incorporation into concrete in order to enhance the material's strength and make the environment protection better. In order to survive the high “potential of hydrogen” of concrete, microbes that are going to be added to concrete need to be able to withstand alkali, and they also need to be able to develop endospores so that they can survive the mechanical forces that are going to be put on the concrete while it is being mixed. In order to precipitate CaCO3 in the form of calcite, they need to have a strong urease activity. Both Bacillus sphaericus and the Streptococcus aureus bacterial strains were evaluated for their ability to precipitate calcium carbonate (CaCO3). These strains were obtained from the Department of Biotechnology at GLA University in Mathura. This research aims to solve the issue of augmenting the tension and compression strengths of concrete by investigating possible solutions for environmentally friendly concrete. The sterile cultures of the microorganisms were mixed with water, which was one of the components of the concrete mixture, along with the nutrients in the appropriate proportions. After that, the blocks were molded, and then pond-cured for 7, 28, 56, 90, 120, 180, 270, and 365 days, respectively, before being evaluated for compressibility and tensile strength. An investigation into the effect that bacteria have on compression strength was carried out, and the outcomes of the tests showed that bacterial concrete specimens exhibited an increase in mechanical strength. When compared to regular concrete, the results showed a maximum increase of 16 percent in compressive strength and a maximum increase of 12 percent in split tensile strength. This study also found that both bacterial concrete containing 106, 107, and 108 cfu/ml concentrations made from Bacillus sphaericus and Streptococcus aureus bacteria gave better results than normal concrete. Both cluster analysis (CA) and regression analysis (RA) were utilized in this research project in order to measure and analyze mechanical strength.

PurposeThe aim of the current study is to inspect the influence of high temperatures on the compressive and split-tensile-strength (STS) of concrete mixtures produced by replacing natural river sand with waste-foundry sand (WFS) at 25%, 50%, 75% and 100%. When the experimental findings and the projected outcomes were compared by IS:456-2000 code equations, the STS results predicted by the suggested mathematical equations exhibit lower variations. It is proposed to employ the presented mathematical formulas to evaluate the STS of concrete cylindrical specimens at higher temperatures.Design/methodology/approachAfter fabricating, concrete mixtures were allowed to cure for 28 days. For the purpose of avoiding explosive spalling during the heating process, concrete samples are taken out from the curing chamber after 28 days and allowed to dry for two days. The manufactured concrete specimen is exposed to 100 °C, 200 °C, 300 °C, 400 °C, 500 °C and 600 °C temperatures for a duration of 2 h. After the specimens have cool down to room temperature (RT), the physical test, ultrasonic-pulse-velocity (UPV) test, compressive strength test and STS test are carried out.FindingsWith an increase in WFS content, concrete specimens' residue compressive-strength and STS decreases. The STS of samples declines as the WFS content rises with increase in temperature interval. According to the UPV test, the concrete samples quality is “good” up to 400 °C; after 500 °C, it ranges from “doubtful to poor.” The UPV values of various mixes declined as the temperature increased. Mass losses increase with exposure to greater temperatures and with an increase in the proportions of WFS in concrete specimens. For mixtures MWFS-0, MWFS-1, MWFS-2, MWFS-3 and MWFS-4 (0%, 25%, 50%, 75% and 100% WFS content), no cracks were present on any of the samples below 400 °C. Concrete surfaces start to show cracks whenever the intervals of temperature increase above 400 °C.Originality/valueIn this investigation, WFS elements are totally substituted for natural sand in concrete mixtures. The residue strength properties, including residual compressive strength and residual STS, were found to be lower after exposures to greater temperature when comparisons were made to referral mixtures. When comparing specimens’ compressive strength, higher temperatures have more effects on the STS of samples with higher WFS contents.

Influence of bacteria on compressive strength and permeation properties of concrete made with cement baghouse filter dust

In recent years, a growing focus has been on creating eco-friendly concrete alternatives, garnering increased attention and support. Using natural fibers in the construction industry will minimize the exploitation of natural raw materials and promote sustainability in the construction industry. This work aims to investigate the influence of palmyra fruit mesocarp fiber (PFMF), Polyolefin fiber (PF), and glass fiber (GF) on the production of self-compacting concrete (SCC). The fiber content was used in three ratios, 1, 1.5, and 2%, as an alternative to fine aggregate. This research was conducted in two phases. In the first phase, a preliminary investigation was carried out to find the maximum adding percentage of fiber content in the successful production of SCC. The mechanical characteristics (compressive, split tensile, and flexural strength) and durability (water absorption, Acid attack, and ultrasonic pulse velocity) were evaluated. The second phase incorporates the fresh characteristics (T500 and slump flow). Adding 1.5%(PFMF/PF/GF) with 10% SF in SCC significantly enhanced the mechanical and durability properties. The compressive, splitting tensile strength, and flexural strength at 28 days increase to 4.30 MPa, 120 MPa, and 4.3 MPa compared to SCC. Scanning electronic microscopic (SEM) and X-ray diffraction (XRD) analysis was performed to evaluate the microstructure of concrete samples. Overall, the incorporation of up to 1.5% as a replacement of fine aggregate in manufacturing fiber-blended SCC mixtures can be recommended.

This study is mainly concerned with conducting experimental investigation for testing the suitability of plastic and demolished waste as a partial replacement in concrete mix. In the present scenario, no construction activity can be imagined without using concrete. Concrete is the most widely used building material in construction industry. As it is widely used for construction of various structures, the economy is dependent upon the cost of material used in making concrete. On the other hand, due to rapid urbanization and industrialization all over the world, huge quantities of plastic waste and demolished waste are being generated. The disposal of these wastes is a very serious problem because, it requires huge space and also it causes environmental pollution. In this situation, construction industry is in need of finding cost effective materials for increasing the strength of concrete. So, in this project it is dealt with the possibility of using the plastic waste and demolished waste as the partial replacement of fine aggregate and coarse aggregate in concrete mix. In this perspective, it is aimed at comparing the properties of conventional concrete mix with the concrete mix prepared using plastic waste and demolished aggregate. In the present experimental investigation, plastic waste is used as replacement of fine aggregate partially by 10% and coarse aggregate is replaced with demolished aggregate partially by 0%, 10%, 20%, 30%, 40% and 50%. The conventional mix has been designed for C-25 grade concrete. In this investigation seven mixes are prepared; the specimens used are cubes of size 150mm length, 150mm width and 150mm depth, cylinders of size 150mm diameter and 300mm of height and flexural beam moulds of size 500mm length, 150mm width and 150mm depth. v Initially, conventional mix is prepared by using conventional materials (cement, natural sand, natural aggregate and water) and their physical and mechanical properties were evaluated. Now, the concrete with recycled wastes are prepared and these are also tested for their properties, likewise all the seven mixes were prepared. For every mix 18 specimens (6 cubes, 6 cylinders, 6 flexural beam specimens) were casted and thus totally 126 specimens were prepared. Specimens of every mix were tested for compressive strength, splitting tensile strength and flexural strength test at 7 and 28 days after curing. With constant percentage replacement of plastic waste in place of sand and varying percentage replacement of coarse aggregate with demolished aggregate, it is found that the density of concrete can be varied from 2500 to 2100 kg/m3. The workability of fresh concrete was decreased with increase in addition of recycled aggregate. From the results it is found that by replacing the natural sand and coarse aggregate by plastic waste and recycled aggregate in the normal concrete, compressive strength (fck), split tensile strength (ft) and flexural strength decreases with increase of recycled wastes. From the experimental investigation, it is concluded that fine aggregate replaced with 10% of plastic waste and coarse aggregate replaced with 10% of recycled aggregate, the properties of fresh concrete were good and also it reached the target mean strength of conventional concrete.

Steel Fiber is found to be the most suitable for increasing strength of concrete mix. Using Steel Fiber would increase some cost but it gives return many times of its cost as a increasing of Compressive strength, Split Tensile Strength, Flexural Strength and as well as provide better stability against Earthquake as the need for greater importance as a drawn-out arrangement in the Indian concrete industry. In the present analysis, we have added steel fiber i.e. 0.5 % to 2.0 % of cement content in concrete mix for getting better test results. The focus of this research is to Increase strength of concrete mix in various manner for getting high heights in construction industry. This study examines the effect of using steel fiber with silica fume in High Strength Concrete Mix i.e. M 60. Total 270 concrete specimens were cast in this study. The specimens were prepared for the concrete mix of M 60 grade using w/c ratio 0.32. The effects on different properties of concrete with Steel Fiber added concrete mix were evaluated in this study. The specimens of concrete mixes were tested for compressive strength, flexural strength, split tensile strength and carbonation test. Test results of the samples show that the strength of concrete mix increases with the use of Steel Fiber added concrete mix as 0.5 % to 2 % of cement content in M 60 Design Concrete mix. It is also found that carbonation depth for Steel Fiber added concrete mix concrete mix is few more as compared to Normal OPC M60 Design concrete mix. The overall results of this study show that Steel Fiber added concrete performs well in various strength tests with some modification in the mix design.

Natural material/fiber should be used in the construction industry as it finds low cost and improve the properties of the material. Jute fiber is used in research study and carried out an experimental investigation on the mechanical properties of the jute fiber reinforced concrete (JFRC). Natural available jute fiber was chopped to the desired length and it was mixed in concrete to produce JFRC. The chopped jute fiber added in three different percentages i.e. 0.5%, 1.0%, & 1.5% in three various concrete mixes (M25, M30 and M40). Additionally, JFRC concrete specimens cured in the acid medium and examine the compression strength, split tensile strength, and strength reduced under acid curing. Workability results indicated that the slump value (workability) reduced as an increased amount of jute fiber in the concrete specimens. Also, the compressive strength reduced in the acid curing as compared to normal curing. Additionally, Jute fiber increased the compressive and tensile strength of every concrete mix. This research study revealed that natural fiber (jute fiber) can be used as additives to enhance the durability and strength of concrete.

Concrete is the second most consumed material in the world after water and it is used most widely in the construction industry due to its high compressive strength and other properties. This paper deals with an experimental investigation on the characteristics of self-compacting concrete (SCC) and self-compacting and self-curing concrete (SCSCC) prepared by (i) partially replacing coarse aggregate with light weight aggregate (LWA) and (ii) adding super absorbent polymer (SAP) in the form of sodium polyacrylate as a self-curing admixture to cure the concrete internally at ambient temperature. 60 concrete cube specimens (SCC and SCSCC) and 60 concrete beam specimens (SCC and SCSCC) were cast for determining the compressive strength and flexural strength. Silica fume (SF) (11% of weight of cement) and superplasticizer (SP) (1% of weight of cement+silica fume) were used in all the test specimens. The self-compacting concrete (SCC) specimens were cured in water at ambient temperature for 7, 14, 21 and 28 days in the conventional manner. The SCSCC specimens were self-cured. The conventional Slump, T50cm slump, J-ring, V-funnel, U-box and L-box tests were carried out on fresh SCC and fresh SCSCC having different proportions. The compressive and flexural strengths of SCC as well as SCSCC in the hardened state were also determined. All the concrete types viz., SCC, SCSCC-1 (0.15% SAP), SCSCC-2 (0.3% SAP), SCSCC-3 (10% LWA) and SCSCC-4 (15% LWA) considered in the present work satisfy the flow criteria. For all the concrete types, both the compressive strength and flexural strength increase with age. SCSCC-2 gives the highest value for compressive strength as well as flexural strength at any age compared to others. SCSCC-4 gives lowest value for compressive strength as well as flexural strength at any age compared to others. SCSCC-1 and SCSCC-2 have better flexural strengths compared to SCC and SCSCC-3 and SCSCC- 4.

Strength and durability characteristics of concrete made by micronized biomass silica and Bacteria-Bacillus sphaericus

The use of recycle materials as concrete ingredients has gained popularity because of increasingly stringent environmental legislation. This research paper check the possibility of replacement of sand (Fine aggregate) by marble powder recovered from marble slurry waste of marble processing units from 0% to 20 %, in production of concrete. This Research paper explore the mathematical modeling of compression strength of concrete cube specimens cured at 7 & 28 days, Split Tensile Strength at 28 days and Chloride penetration resistance of cylindrical concrete specimens cured at 28 days incorporating Marble Powder. Experimental investigation done on various concrete specimens to acknowledge compressive, split tensile strength and chloride penetration. Ordinary Portland cement (OPC) has been substituted with 0%, 10%, 15% and 20% by Marble Powder than after Concrete Cubes & cylindrical specimens prepared accordingly. Compressive strength test, Split Tensile Strength Test has been done concrete specimens and Rapid chloride permeability test (RCPT) has been done on cylindrical specimens. Three predictive regression models has been developed, one for compression strength (CS) of concrete cubes at 7, 28 days and second one for split tensile strength (STS) of concrete samples at 28 days age and last model for RCPT value i.e. charge passed Q@28days in cylindrical concrete specimens. Chloride penetration predictive Model Q @ 28 Days has value of 0.93, 0.69, 200.11 and 0.022 for R Square, Adjusted R Square, Standard Error, and P value. All predictive math models has been confirmed by data in complete range and has superior precision, correlation with experimental data and results.

To address the growing demand for environmentally friendly building materials, increasing attention is being given to adding natural fibers to concrete. While incorporating natural fibers enhances stability by reducing flow, their use in self‐compacting concrete (SCC) presents challenges in maintaining flowability. This study investigates the impact of mono and hybrid natural fibers on the fresh and mechanical properties of SCC, aiming to create more sustainable and cost‐effective concrete by identifying optimal dosages without using mineral admixtures. Abaca fiber (AF) of 50 mm length at a dosage of 0.25% and 0.5% and basalt fiber (BF) of 12 mm length were incorporated in SCC from 0.25% till 2% at 0.25% increment, and the optimum level of usage was identified based on the fresh property tests like slump flow diameter, T500 test, and mechanical tests like compressive strength and split tensile strength after 7 and 28 days of normal water curing. It was observed that AF of 0.25% was considered the optimal dosage, as its compressive strength and tensile strength at 28 days was 4.25% and 8.03%; 11.42% and 6.84% greater than conventional concrete, and AF of 0.5% mix. BF with 0.25%, 0.75%, 1.25%, and 1.75% provided good strength in all parameters, and 1.25% was its optimum dosage. In hybrid fiber mixes, the optimal dosages from mono fiber mixes were combined, and their mechanical behavior like compressive strength, split tensile strength, impact strength, and flexural strength was tested, and the selected specimens were analyzed for microstructural changes using scanning electron microscopy (SEM) to validate the results. The finding indicated that 0.25% AF and 0.25% BF mix achieved better flowability and the highest compressive strength compared to other combinations. In addition, the mix of 0.25% AF and 1.75% BF demonstrated tensile, impact, and flexural strength improvements of 21.42%, 8.21%, and 94.19%, respectively, over control concrete. It is concluded that AF‐based SCC (A‐SCC) and BF‐based SCC (B‐SCC) could not comply with EFNARC norms requiring increased superplasticizer for flow, but the strength parameter was higher in FR‐SCC than the conventional SCC.

Development of sustainable concrete using recycled coarse aggregate and ground granulated blast furnace slag

SCC (Self compacting concrete) can fill formwork and encloses reinforcing bars under gravity and maintains homogeneity without vibration. SCC shortens the period of construction, guarantees compaction in confined zones, moreover terminates noise due to vibration. The wide spread application of SCC is restricted because of the high cost for the production of SCC with high cement content and chemical admixtures. In order to make the production of SCC economical, and to reduce the high cement content the Ordinary Portland Cement in SCC can be blended with pozzolanic materials like rice husk ash and supplementary cementitious materials like fly ash. In this paper the fresh state properties and mechanical properties such as compressive strength, split tensile strength and flexural strength of SCC with ternary blends of rice husk ash (RHA) and fly ash (FA) were studied. For this purpose, different mixes were prepared by replacing Ordinary Portland Cement (OPC) with 5%, 10%, 15% and 20% of rice husk ash (RHA) and the percentage of addition of fly ash (FA) is fixed as 15% for all these mixes. It was observed that the specimen incorporating 10% of rice husk ash (RHA) and 15% of fly ash (FA) as ternary blend exhibits better mechanical properties such as: Compressive, split tensile and flexural strengths at 28 days of age as compared to traditional mix of SCC without RHA (Rice Husk Ash) and FA (Fly Ash). This research demonstrates that the ideal percentage for a mixture of rice husk ash (RHA) and fly ash as ternary blend is 10% and 15% respectively.