The effect of glass powder on physical and mechanical properties of hardened cement paste

The article analyses the effect of finely crushed glass on the properties of hardened cement paste. Materials used for the test: Portland cement CEM I 42.5 R, finely crushed glass (particle size ≤75 µm), and water. Seven compositions of cement paste mixes with different amounts of crushed glass (0%, 5%, 10%, 15%, 20%, 25%, 30%) added by weight of cement were designed. Compressive strength, density and ultrasonic pulse velocity of modified hardened cement paste with different content of crushed glass were measured in the tests. The test results revealed the increase of density, ultrasonic pulse velocity and compressive strength in specimens of hardened cement paste containing 5% and higher percentage of crushed glass after 7, 28 and 56 days of hardening. Microstructure tests revealed that crushed glass had an effect on the microstructure of hardened cement paste after 7 days of curing. X-ray analysis revealed the effect of crushed glass on the physical composition of hardened cement paste hydration products. Hardened cement paste containing 5% of crushed glass by weight of cement was found to have higher strength and density compared to unmodified cement paste.