Exploring macroscopic and microscopic impacts of alcohol amine modified with water-reducing agent on cementitious material and its application

Abstract

In order to meet function requirements of slope protection and ecology for grass-planting concrete with a random porous structure, this study proposes two typical alcohol amines, namely, water-reducing agent modified triethanolamine (TEA) and diethanol monoisopropanolamine (DEIPA), as admixtures for the production of grass-planting concrete. The crystal structures, elemental ratios, and hydration products of cementitious materials with modified alcohol amines were investigated to explore their mechanism of action, reinforcement, and appropriate dosage. The compressive strength of cementitious materials and the spread of mortar made from modified alcohol amines were investigated to evaluate their impact on the compressive strength and workability of grass-planting concrete. The results show that modified TEA can more uniformly reduce the calcium-silicon ratio of the hydration products, leading to enhanced crystallization and densification at a dosage of 0.08%. At a dosage of 0.16%, modified DEIPA can effectively promote the hydration of tricalcium silicate and the secondary hydration of generated calcium hydroxide. The reduction in calcium hydroxide content resulted in an increase in strength. Both these amines enhance the bonding ability of cementitious materials. The spread of the modified cementitious materials is further improved, and suitable cementitious materials with a low water-cement ratio can be obtained for making grass-planting concrete to create uniformly wrapping coarse aggregates with the cementitious material. Modified TEA and modified DEIPA significantly increased the 28-day compressive strength of cementitious material by more than 104%, and the improvement effect of modified DEIPA was significantly better than that of modified TEA. The modified alcohol amines show great potential for practical application in production.