Papers by Keyword: Hydraulic Cement

Abstract: This paper investigates an experimental study of cement-stabilized lateritic soil (CSLS) for road construction. The investigation focused on the mechanical properties and the potential of using biomass bottom ash (BBA) as aggregate materials based on the soil-cement standard of Thailand. CSLS specimens were prepared with different contents of BBA (40%, 60%, 80%, and 100%) and hydraulic cement (3%, 5%, and 7%). A series of unconfined compression tests were carried out to present the strength development of the mixtures. The strength development index value indicated the feasibility of using BBA as aggregate materials with the replacement of the lateritic soil (LS) mass by 60% or more. The replacement of LS by BBA of 80% with 5% cement for soil-cement subbase, and 7% cement for soil-cement base courses, is recommended.

Abstract: The purpose of this paper is to report the results of an investigation on cellular lightweight concrete-filled steel tube columns using hydraulic cement (HCLCFT). The specimens have a circular cross-section with a diameter of 125 mm and a height of 750 mm. The studied variables are hollow steel tube wall thicknesses, and two different cement types; hydraulic cement (HC) and ordinary Portland cement (OPC). The cellular lightweight concretes have the targeted ultimate compressive strength of 15 MPa. A total of 12 column specimens were tested under incremental axial loading to their failure. According to the test results, the HCLCFT columns exhibit linear elastic behavior up to approximately 85-90% of their axial load capacities. After that, the behavior of the columns is nonlinear until their failure. This nonlinear phenomenon can be classified as the strain-softening type. It was found that the HCLCFT columns were failed due to cracking and crushing of the concrete core, as well as local buckling of the hollow steel tube. Finally, by comparing the efficiency of the hydraulic cement to that of ordinary Portland cement in the cellular lightweight concrete-filled steel tube column utilized in this study, it can be stated that the hydraulic cement can be used in alternative to ordinary Portland cement.

Abstract: The feasibility of calcium carbonate-based cements involving the re-crystallization of metastable calcium carbonate varieties has been demonstrated. Two cement compositions were obtained by mixing either calcium carbonate phases (cement A) or a calcium carbonate and a calcium phosphate phase (cement B) with an aqueous media. These cements set and hardened after 30 minutes and 90 minutes respectively. The final composition of cement A was calcite and aragonite whereas cement B lead to a carbonated apatite analogous to bone mineral. Despite poor mechanical properties the presence of a high carbonate content in the final phase might be of interest to increase the cement resorption rate and to favour its replacement by bone tissue. First assays of implantation performed on fresh anatomical pieces (fresh cadavers) at 37°C revealed important advantages of such cement compositions: easiness of use, rapid setting, good adhesion to bone, very good homogeneity and stability of the cement.