A novel study on using protein based biopolymers in soil strengthening

New protein-based biopolymers are introduced in this study to stabilize dune sand. Since the conventional soil stabilization materials, especially cement, have harmful effects on the environment, alternative eco-friendly materials, casein and sodium caseinate salt biopolymers have been used in this study to reduce environmental concerns. Casein and sodium caseinate biopolymers obtained from milk were added to dune sand, and mechanical properties of biopolymer treated sand were investigated through a series of laboratory tests. The effects of biopolymer content, curing time, curing temperature, and fat milk content on improving sand were studied by unconfined compression test. The results showed that compressive strength of biopolymer treated sand was increased when the curing time had passed, and biopolymer content increased. Moreover, temperature can be effective on improving compressive strength of samples treated by casein and sodium caseinate. The positive influence of curing temperature on compressive strength of modified soil was estimated to be up to 60 degrees C. In addition, direct shear test, leaching test and California bearing ratio (CBR) test alongside microscopic observation by scanning electrons microscopy images (SEM) were performed. On the whole, the protein-based biopolymers propose a strong potential as additives for soil treatment rather than some material such as cement and chemical polymers. (C) 2018 Elsevier Ltd. All rights reserved.