The shear behavior and ductility property of beams, retrofitted with cement matrix composite and epoxy binder are compared in this study. Ten shear deficient beams were casted out of which eight beams were retrofitted. Four beams were retrofitted with epoxy binder, and remaining four beams with cement matrix composite. Glass fiber and sisal fiber were used for retrofitting. Cement matrix was prepared with silica fume and superplastisizer. The fibers were diffused in the cement matrix. Four point bending test was performed to analyze the ultimate load and deflection at the mid span of each beam. All the beams were cracked at the shear span. Retrofitted beams showed a considerable increase in shear carrying capacity. A maximum 64% and a minimum 25% of increase in ultimate load were observed in retrofitted beams. Cement matrix composite was found to be effective in shear strengthening, if fibers with good tensile strength are provided.

Today's world cannot be imagined without the application of concrete. Although as a constituent of concrete stone aggregate is mostly used, there are certain areas on this earth where it is scarcely available which leads to the use of brick aggregate. Moreover, as supplementary cementitious material, use of rice husk ash is beneficial to our environment. So, the study presents the possibility of using the brick aggregate and rice husk ash to the possible extent in making concrete by comparing stone and brick aggregate concrete, with rice husk ash as partial cement replacement. The specimens were prepared using water to binder ratios varying from 0.38 to 0.54. Properties of fresh and hardened concrete were measured using different tests on the specimens.The results of the mechanical tests were also co-related with the microscopic image studies.This study finds that for a higher grade of concrete optimum rice husk ash replacement varies between 5 % to 10 % and for lower grade of concrete the rice husk ash replacement varies between 10 % to 15 %. The study also shows that using rice husk ash, brick aggregate concrete exhibits better improvement in comparison to stone aggregate concrete.

Concrete structures may deteriorate over a period of time. Nowadays, to determine the extent of damage, various tests are being performed that are non-destructive by nature. A proper correlation between destructive testing (DT) and non-destructive testing (NDT) may enhance the use of NDT applications in the field of concrete structures. Although several correlations have been suggested by other authors for standard concrete, the correlation may change with the use of non-conventional materials such as rice husk ash (RHA) and brick aggregate (BA) in concrete. In this paper, NDT methods such as ultrasonic pulse velocity (UPV) testing and rebound hammer testing, as well as DT methods such as compressive strength testing, were performed on a special type of concrete in which BA was used as coarse aggregate and RHA was used as the partial replacement of cement. This modified concrete has been abbreviated as RHA-BA concrete. Material-specific prediction models based on linear regression and artificial neural network (ANN) were established after using the data from concrete specimens. A strong correlation was observed between NDT and DT when the RHA percentage was low. The best correlation between NDT and DT was found at 5% RHA. An RHA percentage beyond this yields a weaker correlation between NDT and DT. The linear regression model along with the k-fold validation technique and the ANN model have both proven to be efficient in predicting the compressive strength of RHA-BA concrete; however, the ANN model has proven to be more efficient than the linear regression model with a lower mean squared error (MSE) and higher R-square values.

Bamboo is a giant grass which generally grows in the tropical and subtropical region around the world. The tensile strength of bamboo which is found to be significantly high makes it suitable to be used as reinforcing material with concrete. It is termed as bamboo reinforced concrete (BRC). In some parts of the world stone aggregate is poorly available and crushed brick is widely used as coarse aggregate in concrete which is termed as brick aggregate concrete (BAC). In the North eastern part of India especially in Tripura the availability of bamboo is enormous and brick aggregate concrete is very widely used. So, in this study an attempt has been made to utilize splint of Bambusa Balcooa species as reinforcing material in the brick aggregate concrete for making concrete beam. Beams using different percentage of bamboo reinforcement were prepared and test procedures were followed to evaluate ultimate load carrying capacity of bamboo reinforced beam. The average tensile strength of bamboo has been found as 287.69 MPa in this study. The ultimate load carrying capacity has found to be increased by 4.88 times in case of bamboo reinforced beam. Experimental results proved bamboo as worthy material to be used as a reinforcing material in concrete elements.

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