Effect of PCE-SP on OPC-CSA Mortar

This data repository contains the results of experimental (isothermal calorimetry, ultrasonic pulse velocity, compression testing, setting time and flowability) characterization of OPC-CSA Mortar incorporating PCE-SP. This research investigated the effect of PCE-SP dosage on the early-age behavior of OPC-CSA-based mortar at early ages. It was hypothesized that increased PCE-SP dosage would extend the workability of OPC-CSA blends. While PCE-SP dosage extended the workability of the control 100% OPC system via delays in the hydration of the silicate phases and its dispersion effect on the cement particles, its effect on the OPC-CSA systems quickly diminished within few minutes because of the rapid ettringite formed from the reaction of ye'elemite (main CSA clinker phase) and sulfate. Meanwhile, additional sulfate from anhydrite (contained in CSA) also competed with PCE-SP in adsorbing to cement particles thereby increasing its demand in the system. the additional surface area created by the dispersion effect of PCE-SP promoted the growth of ettringite in the first hour of hydration resulting in increased compressive strength at 2 hours of hydration. Moreover, the compressive strength of all systems evolved slowly in the first 3 days due to delayed silicate reaction and C-S-H formation. Nevertheless, the 28-days compressive strength was comparable with the control systems.