Investigation of the engineering properties of mortars and concretes substituting micronized zeolite

Engineering characteristics of mortars and concretes prepared with substitution of micronized grinded natural zeolite instead of cement, that has great reserves in Turkey were investigated in this study. CEM I 42,5 R cement, RILEM sand, 10% substituted silica fume, 5%, 10%, 15%, 20% substituted micronized zeolite, powder superplasticizer have been used for the mortars. After a day, 5x5x5 cm cubic specimens were removed from the molds and cured at room temperatures. Compressive strength of mortar specimens were calculated on the 3rd, 7th, 28th and 56th days; water absorption, unit weight, ultrasonic pulse velocity tests were done to mortar specimens on the 28th days. Consequently it is noticed that substitution of 15% micronized zeolite gave approximate results with 10% silica fume substitution. According to the results obtained from mortars 0-4, 4-11,2, 11,2-22,4 mm aggregates were provided and 10x10x10 cm cubic, 10x20 cm cylinderic concrete specimens were prepared. Unit weight, heat of hydration of the mixtures were calculated. Compressive and split tensile strength tests of the concretes were done on the 3rd, 7th, 14th, 21st, 28th, 56th , 90th and 365th days. Chloride ion permeability tests were done on the 7th, 28th and 365th days; modulus of elasticity, poisson ratio were attained on the 28th day; carbonation, ultrasonic velocity, sorptivity experiments were carried out on the 7th and 28th days, therefore water absorption and porosity values were attained. At the end of the tests more durable, high performanced concrete and impermeability results close to silica fume is achieved with zeolite substitution. SEM, F-TIR, XRD, TGA analyses were performed to concrete samples on the 3rd, 7th and 28th days to observe the changes in microstructure. All microstructure experiments gave compatible results with each other and at the end of the experiments a little amount of Ca(OH)2 and quartz; CaCO3 and C-S-H were observed heavily on the concrete specimens. As a result, it is evaluated that micronized zeolite can be used instead of silica fume to obtain impermeability and high performance.