Optimization of Gypsum Composition Against Setting Time And Compressive Strength In Clinker For PCC (Portland Composite Cement)

Abstract

Gypsum is one of the additive raw materials added to the clinker grinding process that regulate the binding time of cement or commonly known as a retarder. This research aims to observe the effect of gypsum added variation on the compressive strength of mortar and the whole quality of Portland Composite Cement at plant 14 P.T Indocement Tunggal Prakasa Tbk. The PCC compositions did prepare with a variation of the addition of 0 - 5% gypsum where the clinker ratio did fix at 75%, and two other additives, namely limestone, and trass did add with a fixed ratio of 1.2: 1. The effect of adding gypsum to clinker measured by performing a mortar compressive strength test and the binding time at the ages of 1, 3, 7, and 28 days. The results of series observation and analysis show that composite Portland cement has the most optimal quality in the addition of gypsum as much as 3.5%, where SO3 content is 1.7%, the initial setting time is ≥ 90, and the final setting time is maximum at 375 minutes.

Improve the Compressive Strength Using a Strength Improver Agent (Sia) in the Cement Industry in Indonesia

“…After the sample meets LOI testing requirements, its chemical content can be measured using an X-Ray Fluorescence (XRF) instrument [34]. Chemical testing is intended to determine the content of major and minor oxide elements in cement using the XRF tool, as shown in Table 2.…”

Sustainable approach to quality assurance in cement-improved soil: applications of handheld XRF for geotechnical solutions

“…This property is attributed to its elevated Sulfur trioxide (SO 3 ) content, a key component of gypsum (Calcium Sulfate Dihydrate CaSO 4 •2H 2 O) [16]. Gypsum, an additive material in the clinker grinding process [17], contains water within its molecular structure and comprises approximately 23.3 percent Ca and 18.5 percent sulfur (S). US10 has less Si and more SO 3 compared to ordinary Portland cement.…”