Investigation of Effect of Mineral Additives on Hydration Behavior of Portland Cement Using Electrochemical Technique

The current study examined the effects of rice husk ash (RHA) and quarry dust (QD) as mineral additives on the setting time, compressive strength, and hydration behavior of Portland cement (PC). When compared to control (PC0), blending QD (20-60%) and RHA (10-30%) into PC speeds up the setting. QD addition reduced the strength of PC and a maximum strength of 55.1 MPa was attained after 4 weeks of curing with 20% of QD (QD20). The addition of RHA increased the strength and a maximum strength of 68.1 MPa was obtained with 20% of RHA (RHA20) blended cement. XRD and SEM analyses confirmed the formation of various crystalline phases of hydration products and their effects on hydration behavior of blended cement. The electrochemical studies illustrated that the values of charge-transfer resistance increase with increasing hydration time. In addition, QD and RHA can affect the charge transfer impedance. Results showed after 4-weeks hydration time, QD and RHA additives can reduce the value of charge transfer impedance and hydration degree of PC paste.