Ductility behaviour of reinforced palm kernel shell concrete beams

This paper presents the results on the structural behavior of palm kernel shell concrete and its comparison with normal weight concrete (NWC). The structural grade palm kernel shell concrete, a lightweight concrete (LWC) produced using palm kernel shell (PKS) an agricultural waste and by-product of the production of palm oil as lightweight aggregate, referred to hereafter as PKSC. The concrete is of grade 30 and the reinforced concrete beams of size 150 mm x 250 mm x 2100 mm were prepared to study the structural behavior. Similar grade concrete using NWC were also prepared and reinforced. The flexural behavior of under-reinforced concrete beams of grade 30 concrete has been studied and the results are compared with NWC beams which were also designed as grade 30 and under-reinforced similar to that of the PKSC beams. Ten percent of silica fume and five percent of class-F fly ash on cement weight were used as additional and cement replacement cementitious materials respectively. Each beam was tested under two-point loading for flexure until failure. It has been observed from the experimental investigation of the beams, that the moment capacity of PKSC beams was higher than NWC beams by about three percent. In addition, the mode of failure observed in PKSC was ductile compared to the brittle failure of NWC beams. Thus, the PKSC beams showed a ductile failure, giving amble warning before failure happened. PKSC beams also exhibited a lot of cracking thus the crack width and crack spacing was small. The other advantage for PKSC beams was deflection. The PKSC beams exhibited higher deflection under constant load until failure, compared to NWC beams that failed in brittle manner without warning. Higher concrete strains for the reinforcement in the PKSC shows stronger bond between PKSC and the reinforcement