Influence of lithium sulfate addition on the properties of Portland cement paste

• The hydration process of cement pastes is proved by electrical resistivity method.
• Lithium sulfate can accelerate hydration reaction and shorten setting time.
• Lithium sulfate has no negative effect on cement long-term strength in this test.

Lithium salts are known to have remarkable effect to restrain alkali aggregate reaction, but the influence on strength and setting time of cement paste is uncertain. This paper presents an experimental approach to study the influence of lithium sulfate on strength and setting time of ordinary Portland cement paste with electrical resistivity measurement and other methods. It is shown that lithium sulfate has the function to accelerate cement hydration reaction, shorten setting time and enhance the strength whether at early age or long-term age as well. Meanwhile, the electrical resistivity development of different samples with various dosages of lithium sulfate reflects that lithium sulfate plays the role of set accelerator and hardening accelerator in ordinary Portland cement paste, and the larger content results in stronger effect. So moderate lithium sulfate is beneficial to adjust setting time and increase early strength as well as long-term strength.