MECHANICAL PROPERTIES AND PORE STRUCTURE OF HIGH STRENGTH CONCRETE WITH THE USE OF SANDSTONE AS FINE AGGREGATE

• Main Author: Ayu Bintang S., Nurmalita
• Format: Theses
• Language: Indonesia
• Subjects: Teknik sipil
• Online Access: https://digilib.itb.ac.id/gdl/view/65331
• Institution: Institut Teknologi Bandung

Sandstone is a material substitute for fine aggregate in concrete mixtures. The physical properties such as fineness modulus, absorption, specific gravity, etc., are comparable to natural sands. However, some variations of sandstone when used in concrete mixture as fine aggregate might affect for both its mechanical and transport properties. In this research, three types of sandstone are used in concrete with W/C ratio of 0.29 and 0.32. As a comparison, natural sand concrete with similar W/C ratio was also mixed. Backscattered electron technique was used to analyse its pore structures. Samples were tested for compressive strength at 7,14,21,28 days, while Young's modulus, and Volume of permeable Pore space (voids) at 28 days. Compressive strengths and moduli for all specimens are relatively comparable. However, sandstone concretes have better pore structure (lower porosity and pore size) compared with that of natural sand. The volume of permeable voids in sandstone concretes are 60% lower than that of natural sand. Small pore size in sandstone concretes contribute to the lower volume of permeable voids. The maximum pore size (mesopore) in natural sand is 2.08 ?m while the average of sandstones is 1.41 ?m. This shows that the use of Sandstone in high-strength concrete could improve the pore structure in the concrete.