RSM-Based Optimized Compressive Strength of Mix Design Concrete Aggregates of Clamshell, Iron Sand, and Epoxy Resin

Abstract

The need for environmentally friendly concrete that has above average compressive strength continues to be pursued to meet the infrastructure needs of humans. The availability of materials derived from organic waste such as clamshells is thought to be used as an aggregate from concrete which is more environmentally friendly when combined with previously known inorganic materials. The purpose of this study was to optimize the compressive strength of concrete-filled with clamshell powder (CSP), iron sand, and epoxy resin. An optimization approach based on response surface methodology (RSM) was used in this study. Iron sand used is 10% (w/w). The CSP used is in the range of 1 to 4% (w/w). The epoxy resin used is in the range of 10.5 to 14.40% (w/w). The temperature and time of curing were carried out in 301 to 333 K and 4 hours, respectively. The age of concrete is measured in the range of 1 to 28 days. The cylindrical molded concrete has a diameter and height of 100 mm and 200 mm, respectively. All samples were measured for compressive strength using the UTM RTF-1350 (capacity of 250 kN). The concrete composition with epoxy resin (11.93%, w/w) to the standard concrete aggregate mixture produced the highest compressive strength (71.49 MPa). However, the addition of CSP as a filler in concrete has provided a compressive strength (31.18 MPa) above concrete by the Indonesian National Standard (SNI). The combination of CSP and epoxy resin under high-temperature curing conditions is possible to increase the compressive strength of concrete to 45.65 MPa.