Influence of curing regimes on compressive strength of ultra high performance concrete

Abstract

The present paper is aimed to identify an efficient curing regime for ultra high performance concrete (UHPC), to achieve a target compressive strength more than 150 MPa, using indigenous materials. The thermal regime plays a vital role due to the limited fineness of ingredients and low water/binder ratio. By activation of the reaction kinetics, the effectiveness of the binder is enhanced which leads to improvements in mechanical as well as durability properties. The curing cycle employed are ambient air curing, water curing and hot air curing. The specimens were exposed to thermal regime at (90 • C/150 • C/200 • C) for duration of 24, 48 or 72 hours at the age of 3rd and 7th day followed with air curing or water curing till 28 days. The results showed a marked difference in compressive strength ranging from 217 to 142 MPa with change in curing regimes. The samples when thermally cured at the age of 3rd and 7th day produced an average ultimate strength of 217-152 MPa and 196-150 MPa, respectively.

Influence of curing regime and steel fibres on the mechanical properties of UHPC

“…40 respectively. Sand was used as a filler and SP was added to the mix to improve workability (Karihaloo et al, 2013;Ramachandra Murthy et al, 2013a, 2013b, 2013cPrem et al, 2013). Five batches of UHPC were cast with varying fibre volumes (called R1, R2, R3, R4 and R5).…”

“…The rate of rise and drop in temperature is 28C/minute. Before being subjected to heat curing, the samples were kept in water and then exposed to a temperature of 2008C for 48 h from the third day, after which they were allowed to attain thermal equilibrium with the atmosphere and then kept in water until testing (Graybeal and Hartmann, 2003;Prem et al, 2013;Yazıcı et al, 2009). testing was carried out on cube specimens under water-saturated surface dry condition, after 3, 7, 14 and 28 d as per ASTM C1609 (ASTM, 2006).…”

“…The literature reveals that the observed compressive strength of UHPC samples is dependent on the hydration of cement, pozzolanic reactions of silica fume at lower temperatures and the combined action of silica fume and quartz at higher temperatures (Zheng et al, 2014). Accelerated curing is needed for proper development of the microstructure of calcium silicate hydrates (Ambily et al, 2013;Cheyrezy et al, 1995;Habel et al, 2006;Prem et al, 2013;Wille et al, 2012). To examine the effect of curing on UHPC samples, compression tests and microstructural studies were carried out on specimens cured with water, steam and heat.…”

Influence Factors on the Properties of Ultrahigh-Performance Fiber-Reinforced Concrete Cured under the Condition of Room Temperature

“…Heat curing and autoclave curing can shorten the curing time, making the second hydration reaction between silica fume and the initial hydration product (calcium hydroxide), and give full play to the pozzolanic activity of silica fume and crushed quartz. Numerous studies have shown that [20][21][22][23][24], heat curing and autoclave curing can improve concrete strength compared to standard curing. Richard and Cheyrez [3] formulated RPC with a strength of up to 800 MPa with steel fibers (10% by volume) and steel aggregate at temperatures up to 400°C and pressures of 50 MPa.…”

Sıcak su kürünün silis dumanı takviyeli çimento harçlarının mekanik özelliklerine ve dayanıklılığına etkisi

“…Silis dumanı takviyeli çimento esaslı malzemelerin kür sırasında ısıl rejime tabi tutulmasının silis dumanını daha fazla aktive ettiği ve böylelikle bağlayıcılık özelliğinin artırıldığı Prem vd. 'de[7] raporlanmıştır. Prem vd.50°C sıcaklıkta su içerisinde kürlenmesini ile tanımlanmaktadır.…”