Experimental Comparison of Fibers and Nanomaterials in Compression Test and Cost of High Strength Concrete in Egypt

Abstract

The present work addresses conducting an experimental comparison between different types and dosages of fibers and nanomaterials in compressive tests and the cost of mixes for high-strength concrete (HSC). This study investigated the materials used in the construction sector in Egypt. The experimental work was carried out to select the optimum percentage of each type of the used nanomaterials, and fibers to achieve the highest compressive strength and low cost. In this work, nineteen concrete mixes were prepared. Nano silica (NS) and nano clay (NC) were used at 0, 1, 2, and 3 % by weight of cement. Also, nano- fumed silica (FS) was used at 0, 1, 2, 3, 5, and 10 %, while silica fume (SF) was used at 10 % by weight of cement. Each type of corrugated round steel fiber (STF), and polypropylene fibers (PPF) were used at 0.5, 0.75, and 1.00 % by concrete volume. The results indicated that the compressive strength of the HSC increases as the percentage of adding nano-fumed silica increases up to 3 % and the economic feasibility of nano-fumed silica in concrete is better than in other nanomaterials such as nano silica and nano clay. Also, using 1 % steel fiber in HSC increases concrete strength significantly compared to conventional concrete without considerably increasing the cost.

CREEP Coefficient and Specific Creep of Engineered Cementitious Composite -Bendable Concrete

“…Since fibers increase the tensile strength of the composite, hence it will reduce the potential cracking and creep. Polypropylene fibers (PP) have high ductility and fine distribution with a lower elastic modulus comparatively, hence enabling the concrete matrix to resist the enlargement of the microcracks at the early age of loading [20]. The presence of PVA solution helps to increase the bond strength, and the existence of the polymeric fibers acts as a bridge between the matrix, fiber, and matrix/fiber interface, which results in stronger and more durable concrete.…”