Evaluation of Strength and Microstructure of Adobe Stabilized with Blended Rubber Latex and Sodium Silicate

Abstract

Adobe stabilized with blended, prevulcanized rubber latex and sodium silicate was developed to enhance the low strength of traditional adobe. Sodium silicate was investigated for its action as a pH stabilizer to maintain the pH and liquidity of rubber latex during the manufacturing process. The study characterized the adobe by its compressive strength, flexural strength and microstructure investigation in terms of surface morphology, chemical analysis, functional groups of molecules and porosity. The results showed that adding 3–5% sodium silicate could preserve the liquidity of 5–10% rubber latex during the mixing process. The study in the functional groups of molecules showed the possibility of sodium silicate as a secondary binder and rubber reinforcement. The investigation of the microstructure of stabilized adobe confirmed that alkaline-stabilized rubber latex could distribute throughout the substrate, bind most of the soil particles and fill the capillary pores when dried. The newly developed sodium-silicate-rubber-clay substrates had better strength when compared with traditional clay adobe, rubber-clay adobe and stabilized rubber-clay adobe with low sodium silicate content. The 3% sodium silicate-10% rubber stabilized adobe had the best performance with compressive strength (3.23 MPa or 237.19% of traditional clay adobe) and flexural strength (1.60 MPa or 298.91% of traditional clay adobe).