Effect of lithium salts on Portland cement/high alumina cement paste hydration

摘要

The quick-setting characteristic of ordinary Portland cement (OPC)/high alumina cement mixtures has been utilized in various applications including the sealing of leaks, fabrication of emergency bulkheads, and rapid walls and road pavement repair. These mixes (with HAC as the minor constituent) provide very early strength within a few hours. Strength development and sulphate resistance at later ages is, however, poor [1-3]. In a previous investigation of the hydration behaviour of a 20% HAC-80%OPC paste using conduction calorimetry [4,5], it was observed that formation of ettringite and delay of OPC hydration in the mixture occurred. The latter is a contributing factor to poor strength development in the system, limiting its applications, especially in load-bearing structural repair.