Progress of research into cotton straw and corn straw cement-based building materials in China

Abstract

This paper reviews the development of cotton straw and corn straw cement-based materials in China. With the use of unmodified straw fibres, the compressive strength of the cement-based material decreases with an increase in corn and cotton straw content, but the rate of decrease is considerably lower than that of wheat and rice straw, mainly because of differences in the strength of the straw. The incorporation of fly ash, urea formaldehyde resin and other materials can effectively improve the mechanical and thermal insulation properties of mixed-type building materials. Three methods of modification are proposed – alkali treatment, grafting treatment and direct addition of a modifier. A multiple linear regression equation between mechanical properties and the content of the main components of the cotton straw cement-based materials is obtained, which provides a theoretical basis to predict and design cement-based block materials. Finally, to address the problems of the mix type (difficult stirring, slow hardening, and energy demands and environmental pollution during the modification process), the concept of a composite-type bionic straw cement-based building material is introduced, which provides direction towards the development of new bionic light straw materials.