Quantitative X-ray diffraction (QXRD) was performed to evaluate the chemical reactivity of new cement (new C). To consider the amount of amorphous material (from chemical reaction of new C), internal standard method was adopted by mixing 10wt.% of TiO2 in total weight of measured sample after removing free water in hydrated samples at different curing dates. The weight change from the free water removal process was recorded. Hydrated samples consist of 20wt.% of TiO2 and 80wt.% of sum of unreacted cement and cement hydrates, whereas anhydrous sample does not contain TiO2. Anticipated chemical reaction from the new C is: New C+ water >CSH+CH+ Ettringite where new C is all X-ray detectable crystalline phases, C-S-H is non-crystalline phase (Xray non-detectable), CH is Ca(OH)2. (b) Discuss the limitation of the used internal standard method especially when there is an amorphous content in the new cement itself. Quantitative X-ray diffraction (QXRD) was performed to evaluate the chemical reactivity of new cement (new C). To consider the amount of amorphous material (from chemical reaction of new C), internal standard method was adopted by mixing 10wt.% of TiO2 in total weight of measured sample after removing free water in hydrated samples at different curing dates. The weight change from the free water removal process was recorded. Hydrated samples consist of 20wt.% of TiO2 and 80wt.% of sum of unreacted cement and cement hydrates, whereas anhydrous sample does not contain TiO2. Anticipated chemical reaction from the new C is: New C+ water >CSH+CH+ Ettringite where new C is all X-ray detectable crystalline phases, C-S-H is non-crystalline phase (Xray non-detectable), CH is Ca(OH)2. (b) Discuss the limitation of the used internal standard method especially when there is an amorphous content in the new cement itself