摘要
This study investigates the impact of Type D additive,Plastiment 83 AM,on the compressive strength and microstructure of Portland Composite Cement(PCC)concrete with a target compressive strength of 18.7 MPa,utilizing a mixing,stirring,and treatment model that simulates batching plant conditions.The study investigated additive dosages of 0%,0.15%,0.25%,0.35%,and 0.40%,with stirring durations of 15 min,2,4,6,and 6.5 h.Compressive strength tests were conducted at the ages of 7,14,28,56,and 90 days on cylindrical specimens,and at 24 h for setting time tests.Microstructural analysis using Energy Dispersive X-ray Spectroscopy(EDX)was performed at 56 days of age.The results showed that the optimal dosage was 0.15%,combined with the addition of Plastiment 83 AM 0.10%at 2 h of stirring,which achieved the highest compressive strength of 20.5 MPa at 90 days.A reduction in compressive strength of the setting time samples from the initial value to 24 h was observed in mixtures stirred for 6 and 6.5 h.A decrease in compressive strength was also observed in both mixtures between 56 and 90 days.EDX analysis revealed different chemical compositions in each mix.At a stirring duration of 6 and 6.5 h,Plastiment 83 AM dosages of 0.35%and 0.40%showed the presence of Magnesium(Mg)and Aluminium(Al)(at 6 h)and Al and phosphorus(at 6.5 h).The presence of inhibited the hydration process,resulting in a very small increase in compressive strength from 14 to 28 days.Magnesium reduced the compressive strength to 75%,and phosphorus to 63%of the target compressive strength.
