High early strength foamed concrete design for structural precast concrete

Abstract

Precast lightweight concrete with specific gravity between 1440 kg/m3 and 1840 kg/m3, and high early compressive strength is one of the alternative materials in responding to the large and fast demand for precast concrete, as well as being easy to transport. This study proposes high early strength foamed concrete as an alternative to precast lightweight concrete for residential construction. The background of this study is considering the limited literature reports related to research on precast foamed concrete for the application of building structural elements. The purpose of this study was to obtain high early strength foamed concrete for structural precast concrete with minimum characteristics, including initial compressive strength of 14 MPa at 3 days of age, 20 MPa of compressive strength at 28 days of age, and specific gravity of less than 1750 kg/m3. There are 3 types of foamed concrete was studied, namely normal foamed concrete, foamed concrete with LDPE, and foamed concrete with water substitution accelerator. Then, compressive strength testing was conducted on cylindrical specimens. The results showed that foamed concrete with 10% water substitution accelerator produced the highest values for the initial compressive strength of 3 days and 28 days of age, 21.64 MPa and 29.27 MPa, respectively, and the specific gravity of 1743 kg/m3.