Walid Hassan

The rapid growth in construction is one of the toughest challenges that faces humanity due to the increasing consumption of the raw natural resources. Such growth has a severe impact on the society since the byproducts of the production of the construction materials threatens the environment and the sustainability of the industry. The construction industry is highly dependable on concrete due to its reasonable durability, fire resistance and reduced maintenance costs. The increasing consumption of concrete had led to a higher depletion rate of the natural aggregates (NA) used in the production of concrete. The usage of demolition wastes as a component for the production of new concrete can reduce the demand on the natural resources and the landfills. The replacement of natural resources in concrete production can be either partial or full. This research aims to study the influence of using two types of natural aggregates and one recycled concrete aggregate (RA) on the shear strength of plain concrete of different concrete strengths. In total, twelve mixes are cast and tested. The shear strength of recycled aggregate concrete (RAC) is compared to those of concrete made of two other types of coarse aggregates available in Kuwait: gabbro (GB) and limestone (LS). The shear strength is based on push-off specimens. The target compressive strength for the natural aggregate concrete (NAC) and RAC were: 20, 35, 40 and 60 MPa. The effect of the type of aggregate on the shear strength and the failure crack are also investigated. According to the experimental results, it was noticed that low strength concrete (LSC) cast with LS performs better in terms of shear resistance when compared to the other two types of aggregates. At higher strength concrete, there is no significant difference in shear strength between concrete cast with different types of NA. RAC achieves less strength capabilities than achieved by the NAC.

Graduated with excellence and honor degree