No abstract

No abstract

This study aims to analyze the engineering properties of cementless grouting materials (CGMs) and derive optimal binder types and compositions that can ensure superior material performance in comparison with ordinary Portland cement (OPC). The presented CGM is an environment-friendly inorganic binder based on ground granulated blast-furnace slag. The material properties of three CGM types with different chemical compositions were evaluated. To assess the possibility of using CGMs in grouting-construction methods, this study followed special grouting-method specifications of the J company in Korea, and tested whether CGM satisfies the performance requirements of a gel time of 20–50 s and homogel strength greater than 2 MPa after 7 days. For OPC and CGM, gel time increased and homogel strength decreased as the water/binder (W/B) ratio of Liquid B increased or as its replacement ratio decreased. Additionally, gel time decreased while homogel strength increased as the absolute weight of the Liquid B binder increased, and a negative correlation was observed between gel time and homogel strength. CGM2 was the optimal binder to ensure excellent material performance compared with OPC. Optimal mixing proportions were 117.8–167.7% W/B ratio, 42.6–56.7% Liquid B volume ratio, and 20.4–43.7 kg binder weight.

This study investigates the effects of the emulsifier content and monomer ratio on the typical properties of the polymer-modified mortars with methyl-methacrylate-butyl-acrylate (MMA/BA) and methyl-methacrylate-ethyl-acrylate (MMA/EA) latexes and obtains basic data necessary to develop appropriate latexes for cement modifiers. The polymer-modified mortars using the MMA/ BA and MMA/EA latexes polymerized with emulsifier contents and at various monomer ratios are prepared for different polymer-cement ratios, and tested to obtain the particle size of the polymer latexes, the glass transition temperature of the polymer film, air contents, water-cement ratios, flexural and compressive strengths, water absorption, and chloride ion penetration. From the test results, the polymermodified mortars using MMA/BA and MMA/EA latexes with the mix proportions of synthesis having emulsifier contents of 5-6% and monomer ratios of 50 : 50 to 60 : 40 for the appropriate mix proportions can be recommended for practical applications. The basic properties of the polymermodified mortars are more affected by the polymer-cement ratio rather than the monomer ratio and emulsifier content, and are improved over unmodified mortar.