Cement production produces a high amount of carbon dioxide, which has a negative impact on the environment. By utilizing waste products instead of cement, environmental degradation can be reduced. The current study was undertaken to study the mechanical and durability performance of concrete by replacing 7.5%, 10%, and 12.5% silica fume (SF) of cement weight. Additionally, coal bottom ash (CBA) was also substituted as fine aggregates with 10%, 20%, and 30%. Compressive strength and indirect tensile strength were the major parameters regarding mechanical properties, while corrosion analysis and sulfate attack were set for durability performance. Sixteen mixes were prepared including a control mix. Out of these, three mixes contained SF, three mixes contained CBA, and eight mixes contained both SF and CBA with 1:2:4 ratio at 0.5 w/b ratio. The results concluded that the addition of 12.5% SF and 30% CBA gives optimum compressive strength and tensile strength. Furthermore, using the SF and CBA reduces the workability of concrete. Furthermore, the use of these byproducts increased the durability in terms of corrosion and sulfate attack.

This study experimentally investigates the mechanical and durability performance of bacteria concrete in terms of density, compressive strength, split tensile strength, and water absorption capacity. The concrete specimens were produced with a ratio of 1:2:4, w/c ratio of 0.45, and having a bacteria dosage level ranging from 1 to 6% by weight of water. To investigate the usefulness of the bacteria dosage level, cubic and cylindrical specimens were cast and tested after 28 days of water curing in a Universal Testing Machine with a constant loading rate. The density of each specimen was also recorded soon after casting and after the curing period ended. Moreover, the water absorption test was similarly conducted on cube specimens at various time intervals to record the penetration depth. The test results of normal concrete (without bacteria) were compared with the ones of the specimens containing bacteria. The optimum level of bacteria was found to be 3.5%, which showed the highest values in terms of compressive strength, split tensile strength, and density. Bacteria tend to generate more crystalline materials inside the concrete mass due to reactions with the surrounding moisture which produces a compact surface, thus strength properties were improved and water penetration was blocked which suggests better durability of the concrete.

Nowadays construction industry is trying to develop energy-efficient and environmentally friendly materials. In this regard, various types of concrete are designed but still, there is a need for a material that is energy efficient and sustainable, on...

Performance of normally produced concrete is extensively examined both in terms of mechanical and durability point of view using natural aggregates, but due to excessive use of natural resources it is important to use recycled aggregate to reduce not...