Study on the Effect of Nano-Silica in Mechanical and Durability Properties of Concrete with Steel Fiber

This study presents experimentally the combined effect of using Nano-silica (NS) and steel fibers (SF) on the mechanical properties of hardened concrete. NS is used as partial cement replacement by different percentages, and SF is used as volume substitution by different percentages. Splitting tensile strength, modulus of elasticity, and flexural strength are evaluated using different combinations between NS and SF. Significant improvement in the mechanical properties of concrete is observed on using NS due to its high pozzolanic activity. The Optimum content of SF is improved splitting tensile strength with different percentages respectively compared to without either NS or SF. Utilizing NS with SF leads to improving modulus of elasticity compared to without either NS or SF. Flexural strength is doubled for using NS and SF compared to without NS and SF.

An Overview of Behaviour of Concrete with Granulated Blast Furnace Slag as Partial Cement Replacement

Ground granulated blast furnace slag (GGBFS) is one of green construction materials that held benefits in producing sustainable and high-quality concrete. GGBFS is commonly used as supplementary cementitious materials in blended cement to reduce the need for Portland cement in mortar or concrete production. An overview of the utilization of GGBFS as partial cement replacement with regards to mortar and concrete properties is presented in this paper. The fresh properties of GGBFS mixes addressed include workability and setting time. While compressive strength, porosity, shrinkage, and resistance to sulfate attack are the reviewed hardened properties. Overall, various studies showed that incorporating GGBFS in mortar/concrete mixes significantly improves mortar/concrete properties depending on the GGBFS replacement ratios. It is anticipated that this review will provide valuable information for a better understanding of the fresh and hardened properties of GGBFS-blended mortar and concrete. Moreover, as there is a growing interest in optimal utilization of GGBFS in Indonesia’s cement and construction industry, this review paper intended to raising awareness of GGBBFS utility regarding its benefit for sustainable construction.

Study on Mechanical Properties of Foamed Concrete Incorporating Palm Oil Fuel Ash and Mussel Shell as Partial Cement Replacement

Concept of sustainable construction has gradually become one of the concern issues in our construction industry in recent years. Concrete which acts as an important construction material has contributed to excessive consumption of natural resources. Simultaneously, tonnes of waste materials were produced from agricultural activity in form of palm oil fuel ash (POFA) while mussel shell from marine hatchery. Utilization of agricultural waste as cement replacement is an option to reduce the environmental impact from the construction industry. In this study, these waste materials were used as partial cement replacement to produce foamed concrete in wet density of 1800 kg/m3. The main purpose of this research is to study the workability and mechanical properties of foamed concrete which contain uniform 20% of POFA combined with 5% to 10% of mussel shell powder (MSP) and mussel shell ash (MSA) respectively. The cube specimens were cast in dimension 100 mm x 100 mm x100 mm to test the compressive strength at 7th and 28th. The cylinder specimens were cast in 100 mm diameter x 200 mm diameter for split tensile test to determine the tensile strength and compression test to determine modulus of elasticity at 28th day. The result showed workability of foamed concrete decreased as more cement was replaced by POFA combined with MSP and MSA. Foamed concrete mixture with 20% POFA and 5% MSP was selected as optimum percentage of cement replacement due to reduction less than 5% compromised performance in compressive strength at 16.52MPa while tensile strength at 1.83MPa.