Development of high strength & lightweight cementitious composites using hollow glass microsphere in a low water-to-cement matrix

It has been a challenge for structural concrete to satisfy both high strength and lightweight, since general lightweight properties have been achieved through the use of lightweight aggregates with inherently weak strength. In this study, a cement composite with high strength and lightweight was developed using very low-specific gravity material of hollow particles. A combination of a polycarboxylate-ether superplasticizer, filler materials, and a low water-to-cement ratio was selected to increase the viscosity of the cement matrix for minimizing floating of the hollow particles. As a result, the developed cementitious composites substantially outperformed the material performance of previously reported lightweight concretes. Compressive strength of 69 MPa and 97 MPa at 28 days were achieved with the density less than 1.5 g/cm3 from ambient and heat-treated curing, respectively. From a reaction perspective, the used hollow particles did not actively participate in the cement-based hydration reaction, which indicated that their role is limited to being very light inert fillers in the designed cementitious matrix. © 2022 Elsevier Ltd