Characteristics of a Two-component Waterborne Acrylic Emulsion Waterproof Coating based on Underground Engineering

Abstract

Acrylic waterproof coatings have good performance, but their application is limited by their high cost. In addition, few studies explored the waterproofing and impermeability characteristics of these coatings. Based on experimental and theoretical analyses, this study prepared a waterproof coating composed of acrylate polymer emulsion (pure acrylic emulsion) and low-cost styrene–acrylate copolymer emulsion (styrene–acrylic emulsion) to improve the performance, reveal the impermeability mechanism, and decrease the cost. Orthogonal and single-factor tests were carried out to analyze the mechanical, waterproofing, and impermeability properties of the coating. The optimal proportion of the waterproof coating was determined. Results show that combining styrene–acrylic emulsion and pure acrylic emulsion can enhance the performance and reduce the cost of waterproof coatings. In addition, performance improvement is positively correlated with the mesh number of heavy calcium carbonate, and the water pressure of an 800-mesh heavy calcium carbonate coating is increased to 1.4 MPa. In the anti-permeability test, the surface of the coating film bulges under the action of water pressure, and the bulges rupture and water seep occurs under continuous pressure. When the dosage of tributyl phosphate is 0.35%, the water pressures under the coating bulges and water seep are 0.7 and 1.5 MPa, respectively. This study can serve as a basis for the study and impermeability evaluation of acrylic emulsion waterproof coatings.