Optimum Oil Palm Shell Content as Coarse Aggregate in Concrete Based on Mechanical and Durability Properties

Abstract

Oil palm shell (OPS) is a biosolid waste in palm oil industry in the tropical countries which could be used as aggregate in concrete mixture. Since 1984, OPS has been experimented as natural lightweight aggregate in research studies to produce lightweight concrete (LWC). Medium and high-strength LWCs using OPS as coarse aggregate were successfully produced. However, higher drying shrinkage and lower mechanical properties for concretes containing higher volume of OPS are reported in previous studies. Therefore, OPS is not fit to be used as full coarse aggregate in concrete mixture and therefore, there should be an optimum OPS content in concrete. In this study, in a normal-weight concrete, normal coarse aggregate was replaced with OPS from zero to 100% with an interval of 20%. Tests such as slump, density, compressive strength in different curing conditions, splitting tensile strength, initial and final water absorptions, and drying shrinkage of cured and uncured specimens were conducted to find out optimum OPS content in concrete. From the test results, it could be summarized that OPS content should not exceed 60% of total volume of coarse aggregate.

Assessment of Workability and Compressive Strength of Rice Husk Ash-Blended Palm Kernel Shell Concrete

“…For 1:1 1 /2:3 mix ratio, the slump values decreased from 60-18 mm as the PKS contents increased from 0-100%; while for decreased from 40-16 mm for 1:2:4 mix ratio with increase in PKS contents from 0-100% and the slump values of concrete produced with mix ratio 1:3:6 decreased from 30-6 mm as the PKS contents increased from 0-100%. This is corroborated with the findings of Sobuz et al (2014) and Maghfouri et al (2018) where decrease in slump values were observed as PKS contents increases. These results indicate that the presence of PKS and RHA decrease the workability of concrete compared with the control for in workability is attributed the rough texture, irregular, flaky, elongated or angular shape and higher bulk density of PKS compare to granite (Maghfouri et al, 2018).…”

“…This is corroborated with the findings of Sobuz et al (2014) and Maghfouri et al (2018) where decrease in slump values were observed as PKS contents increases. These results indicate that the presence of PKS and RHA decrease the workability of concrete compared with the control for in workability is attributed the rough texture, irregular, flaky, elongated or angular shape and higher bulk density of PKS compare to granite (Maghfouri et al, 2018). The reduction of workability of RHA-blended PKSC can also be attributed to the increase in replacement level of PKS having higher fine particles leading to increase in its surface area compared with granite as indicated in the gradation curves (Figure 2) can cause an increase in water demand.…”

“…RHA-blended PKSC containing 20% PKS produced with 1:1 1 /2:3 mix ratio exhibited the slump value in the neighborhood of the lower limit acceptable for good workable concrete. However, the workability of concrete can be improved by adding effective superplasticizer to the concrete mixes to increase the concrete slump value (Maghfouri et al, 2018).…”

“…As reported in the literature, PKSC has a lower density and strength than NWC (Raheem et al, 2008;Olusola and Babafemi, 2013;Fapohunda et al, 2015). However, the lower density makes PKSC to be beneficial for use as lightweight concrete (Maghfouri et al, 2018;Olanitori and Okesanmi, 2019). Concrete produced from lightweight aggregate (LWA) with the density of less than 2000 kg/m 3 and minimum compressive strength of 17 N/mm 2 are referred to as structural lightweight aggregate concrete (SLWAC) (ASTM C 330/C 330M, 2014;ACI 213R-03, 2003).…”

Challenges of Using Agricultural Solid Wastes as Aggregate in Structural Concrete

“…There was also aware of using high volume OPS aggregates in concrete mixtures. A recent study [13] on the mechanical and durability properties (in terms of water absorptions and drying shrinkage) of OPS concrete concluded that the volume of coarse OPS aggregate in the concrete mixture should not exceed from 60% of total volume of coarse aggregate. This limitation is due to the fact that concrete containing more than 60% OPS aggregates showed high drying shrinkage.…”