Influence of Layer Thickness and Plasticizers on the Characteristics of Cement-Stabilized Rammed Earth

Abstract

Cement-stabilized rammed earth (CSRE) is used for load-bearing walls. CSRE is a monolithic construction that is constructed by compaction of processed soil in a rigid formwork. The compacted layer thickness varies between 100 and 150 mm. Generally, a dry density in excess of 1,800 kg/m3 is achieved for CSRE through compaction. Apart from the need for very rigid/stiff formwork, a considerable amount of compaction energy is expended in achieving such high dry densities. The paper (1) examines the influence of layer thickness on characteristics of CSRE; and (2) explores use of superplasticizers for reducing the compaction energy. Considering four different layer thicknesses, the strength and stress–strain characteristics of CSRE were experimentally determined. The compaction energy and characteristics of CSRE were monitored by using different dosages of superplasticizer additive. The major findings of the investigations are (1) optimum compacted layer thickness giving maximum compressive strength for CSRE is 90–100 mm; and (2) the compaction energy reduces by half with the use of 0.65% of superplasticizer with enhanced strength and modulus for CSRE.