ئەز   Qahar Mustafa Abdullah

This study aims to investigate the rheological properties, mechanical strength, and structural behaviour of self-compacting concrete (SCC) deep beams incorporating waste polyethylene terephthalate (PET) as partial replacement of fine and coarse aggregate. The replacement ratios were set at 10% and 20%. The engineering properties of SCC were examined such as slump flow test, slump flow time (T50cm), J-ring test, V-funnel and L-box test, compressive strength, splitting tensile strength, flexural strength. Additionally, the structural behaviour of the beams was assessed based on load-deflection curves, load-strain relationships, and cracking patterns. The results indicate that a replacement ratio of up to 10% has a minimal impact on the reduction of load-bearing capacity of deep beam. Furthermore, visual examinations were performed to determine the mode of failure. It was found that a certain amount of waste plastic can be used in structural applications without compromising the flexural characteristics of reinforced concrete beams.

High Strength Concrete (HSC) has the ability to strengthen deteriorated concrete members. The performance of HSC incorporating waste polyethylene terephthalate (PET) fibers as a repair material for concrete structures has not been examined extensively in current literature. Thus, more investigations are considered essential in this direction. This endeavor is devoted to examining the flexural behavior of hybrid reinforced concrete beams (HRCB) made with normal concrete (NC) repaired by or bonded to HSC containing waste PET fibers (FRC). The workability and mechanical properties of fresh and hardened FRC were investigated. Moreover, the efficiency of HSC overlay as a repair material for NC substrate was evaluated through a slant shear test (SST) which considered four modes of roughening of the NC interfacial surface. A third-point load test was used to evaluate the structural behavior of the HRCB. The …

The aim of this study is to review the published researches which discussed repairing and strengthening the deteriorated normal strength concrete with overlay repaired materials. Throughout this literature, several subjects will be discussed such as the repairing of deteriorated concrete members, the main causes of this problem, compatibility between overlay material and concrete substrate, common repair materials, surface preparation of the substrate, etc. In addition, the present review covers the test methods for evaluating the adhesion or bond strength of the hybrid concrete. There are many tests available in this direction but among these the slant shear test considers the widely recommended one to obtain failure modes at the interface as an adhesive failure and monolithic as a cohesive failure. A flexural strength test considering a three-point load system was considered as well in the review to examine bonding for the hybrid concrete. The experimental observations for many sorts of concrete material were discussed and conclusions were drawn to show the gap of knowledge in the field of strengthening deteriorated concrete structures.