Experimental Study on the Relationship Between Grouting Pressure and Compressive Strength of Hardened Cement Paste

It is very difficult to predict the compressive strength of grouted hardened cement paste in the fracture areas when grouting technology is used for seepage prevention and reinforcement. In this paper, according to the Powers model of hardened cement paste, combined with indoor and field test data analysis, this study found that: (1) Under the condition that grouting pressure is zero, strength of hardened cement paste decreases with the increase of grout water cement ratio (W/C). Based on Powers model, the relation between grout strength of hardened cement paste and the ratio of paste mixing water is established; (2) The strength of grouting hardened cement paste in cracks increases with the increase of grouting pressure. The mechanism is that with the increase of grouting pressure, the real W/C of cement paste decreases, the paste is denser, as a consequence, the strength of grouting hardened cement paste is higher. (3) The calculation model of compressive strength and grouting pressure of grout hardened cement paste is established, and the compressive strength of grout hardened cement paste can be predicted according to grouting pressure and type of cement. The research results can provide the basis for the prediction and design of the compressive strength of grouting cement paste.