Development of High-Compressive Heavyweight Concrete Based on Portland Cement and Supplementary Cementitious Materials

Abstract

The manufacture of optimized heavyweight concrete takes into consideration the type of aggregates, composition of blended cement, water-to-cement ratio, additives etc. The density of concrete depends mainly on the specific gravity of the used aggregates. Generally, concretes with specific gravities higher that 2600 kg m-3 are called heavyweight concretes and aggregates with specific gravity higher than 3000 kg m-3 are considered as heavyweight aggregates according to EN [1,2]. Concrete is a low cost material and easy to produce in varied compositions when compared to other shielding materials based on ceramics [3]. It is composed of a well-proportioned mixture of light and heavy nuclei. It is therefore efficient both in absorbing gamma rays and in slowing down fast neutrons by elastic and inelastic scattering [2]. Light materials, especially hydrogenous materials which contained in the water of hydration of the set cement (concrete) attenuate fast neutrons as a consequence of the high cross-section of hydrogen [4].

Optimization of cementitious composite for heavyweight concrete preparation using conduction calorimetry

“…Likewise, oxide composition of CEM I 42.5 R, granulated blast furnace slag, metakaolin, and limestone is depicted in Table 2. The procedure for preparing concrete samples of HWC is described in [23,24]. After mixing, the specimens were kept in cubic (150 × 150 × 150 mm) and prism (100 × 100 × 400 mm) molds for 24 h at room temperature and covered with plastic in order to avoid the drying of samples.…”

“…The heat flow of CEM I 42.5 R and CEM_75_A is faster and with cumulative heat exceeding 250 j g −1 after 2 days. They were previously used in the preparation of high strength heavyweight concretes [23]. But, some cracks were observed on the surface of samples due to the thermal stress of shrinkage caused by high hydration heat.…”