Effects of water and sawdust additives on thermal effusivity, thermal conductivity and durability of cement-stabilized laterites

Abstract

The effects of water and sawdust additives on the thermal effusivity (e), thermal conductivity (λ), and durability of cement-stabilized laterites were investigated. The thermal effusivity (e) and conductivity (λ) have direct influence on heat transfer and thermal insulation in buildings, and the parameters were determined by hot strip method, which simultaneously estimated e and λ in less than 180 s using a thin rectangular electrical resistance device. The cement-stabilized laterites with sawdust additives exhibited higher thermal insulation than ordinary laterite bricks. Under dry conditions, λ = 0.648 W m-1 K-1, e = 975.4 J m-2 K-1 s-½ for stabilized laterite with 4 % cement; λ = 0.574 W m-1 K-1, e = 893.4 J m-2 K-1 s-½ for stabilized laterite with 4 % cement incorporating 2 % sawdust; and λ = 0.510 W m-1 K-1, e = 828.2 J m-2 K-1 s-½ for stabilized laterite with 4 % cement incorporating 4 % sawdust additives. The samples exhibited mechanical strength satisfying construction criteria for building, i.e., water resistance to dry compression strength ranging from 2.857 to 4.286 MPa.