STUDY OF MACRO MECHANICAL PROPERTIES OF ULTRA HIGH STRENGTH CONCRETE USING QUARTZ SAND AND SILICA FUME

T.Chandra Sekhara Reddy, J.K.Elumalai

Abstract: Concrete is one of the necessary elements for structural work in the modern construction. In the decade, buildings around the world have become higher and so the structural strength demand for concrete is increased, they require high strength concrete. Ultra high strength concrete (UHSC) has been developed in the recent revolution of concrete. The major difference between ultra high strength concrete and conventional concrete is that no coarse aggregate is involved in ultra high strength concrete, but quartz sand, quartz powder are used instead, with high dosage of silica fume. In this present work, an attempt is made to develop ultra high strength concrete using locally available materials, to achieve a target compressive strength more than 180 Mpa. Heat treatment is well known method which can improve the micro structural properties, pozzalanic reactivity of silica fume, quartz powder and also mechanical properties and durability. The curing cycles employed are water curing and hot air curing. The cube specimens of size 70.6 mm X 70.6 mm X 70.6 mm and cylindrical specimens of size 100mm dia X 200mm high were cast and exposed to a temperature of 200 0 c for duration of 24, 48 and 72 hours at the age of 3rd day followed with water curing till the age of 28 day testing. The results showed marked difference in compressive strength ranging from 187 Mpa to 142 Mpa. The samples cured under normal water only produced strength of 116 Mpa with the mix considered. It is observed from the study that quartz powder, quartz sand, duration of temperature affects the compressive strength; hot air temperature curing increased the compressive strength up to 40% nearly when compared with the specimen under normal water curing only

Keywords: Ultra high strength concrete, Silica fume, Quartz power, Quartz sand, Compressive strength, hot air curing

DOI: https://doi.org/10.15623/ijret.2014.0309061