Sustainable Development of Highly Flowable Cementitious Grouts for Semi-flexible Pavement Mixture

Abstract

Grout is a substance with a cement which is characterized by a high strength and it is a high workability, so it can be injected in places of small cracks or places of water leakage. Generally, it is used to repair cracks or defects of concrete, also it can be used to fill the voids under the metal bases or digging anchors. Moreover, grout is used efficiently in the process of production the semi-flexible pavement mixtures. The purpose of this study is to design a sustainable grout using waste and by-products materials, to end as flowable grout for semiflexible pavement mixtures. The mixture of the grout was prepared using Ordinary Portland Cement (OPC), silica fume (SF), paper sludge ash (PSA), superplasticizer (SP), and water. Different proportions of mentioned materials were used to characterizing the developed grout through flowability, compressive strength, and flexural strength tests. Results showed that the flow time increases with increase in the surface area of cementitious materials. Also, the compression strength of the grouts comprised OPC+PSA, revels that there is an optimal dosage: i.e., 15% PSA. Whereas SF generally leads to increase the compression strength. On other side, flexural strength test confirmed the upgrading of developed grouts. As a conclusion, a sustainable grout can be produced with acceptable characteristics when grout constitutes are optimized.