The Effect of Different Mineral Admixtures on Characteristics of Concrete

This paper presents a review of the properties of fresh and hardened concrete by using mineral admixtures fly ash (FA), and silica fume (SF). In manycountries, these materials are already used in manufacturing of concrete. However, these industrial by products is becoming popular throughout the world because of the minimization of their potential hazardous effects on environment. Some of these materials used as replacement for cement. Ultimately it results in the reduction of the cost manufacturing of concrete and reduces environmental pollution. In general, small particle size and higher specific surface area of mineral admixture are favorable to produce highly dense and impermeable concrete; however, they cause low workability and demand more water.  To study the effect of mineral admixtures such as fly ash and silica fume on mechanical properties of concrete under the uniaxial compression experimental studies conducted. The cement was replaced by 10 %, 20 % and 30 % with fly ash and silica fume. The compressive strength test conducted on concrete specimen with different percentages of fly ash and silica fume at age of 7 days and 28 days

Effect of Glass Fiber on Compressive, Flexural and Spliting Strength of Reactive Powder Concrete

Reactive Powder Concrete (RPC) is a new technology in high strength concrete industry. Steel fibers are usually used as reinforcements in RPC mixture. In this research, steel fibers in RPC mixture are replaced by fiberglass. The volume of fibers used are 1%, 1.5%, and 2%. Curing process by steam curing in 12 hours. The concrete was tested after 28 days including compressive test, split tensile test, and flexural test. The result shown that optimal value of fiberglass added to mixture was 2% from total volume with compressive strength value at 127.38 MPa, split tensile strength at 9.844 MPa, and flexural strength at 10.36 MPa. Density of fiberglass reinforced concrete at optimum volume is 2224.3029 kg/m3 it was lower than steel fibers reinforced concrete at optimum volume which has density of 2310.385 kg/m3

Effect of Polypropylene Fiber Reinforced on Properties of Concrete

This paper investigates on analyzing the effects of use of Polypropylene fiber in the mechanical properties of concrete. One ofthe main tasks of the construction industry is to increase the strength and reliability of structures while reducing construction costs. Effective use of fiber reinforced concrete is likely to lead to reduction in reinforcement. Three mixes used polypropylene fiber with content 1.0%, 1.5%, and 2.0% percent. To provide a basis for comparison, reference specimens were cast without polypropylene fiber. The test results showed that the increase of mechanical properties (compressive strength) resulting from added of polypropylene fiber was relatively high.</jats:p

Effect of Superplasticizers to Enhance the Properties of Concrete

This study aimed to study the effects of asuperplasticizing admixture, namely, Sikament-NN superplasticizer, on concrete properties, such as workability and compressive strength. Experiments were performed on different concrete mixes with water–cement ratios of 0.50, 0.55, and 0.60. The superplasticizer dosages by weight of cement were 0%, 0.8%, 1%, and 1.2%. The experiments were classified into two phases: the first phase focused on the effects of superplasticizer admixture on workability and compressive strength, and the second phase determined the influence of superplasticizer admixture on concrete quality by reducing the amount of mixing water. Results showed that the addition of superplasticizer admixture improved workability and compressive strength. The experiment program included tests on workability, slump test, and flow table. For hardened concrete’s compressive strength test, we compared the properties of superplasticizer-based concrete with those of concrete without superplasticizer. The superplasticizer led to a significant water reduction but maintained workability.</jats:p

Evaluation of the superplasticizer effect on the workability and strength of concrete

The adverse effects of temperature on the properties of fresh concrete include increased water demand, shorter setting time and increased slump loss. Superplasticizer (SP) is important for enhancing the workability and setting time of concrete in hot weather. Hence, an experi-mental investigation was conducted to determine the optimum dosage of an admixture and to study the effect of over dosing this admixture. Concrete mixes with SP dosages of 0.8%, 1% and 1.2% by weight of cement were prepared along with a control mix (water/cement ratio of 0.55). After casting, the concrete samples underwent normal curing. Among the properties of fresh concrete determined were compressive strength as well as workability. The over dosage of SP appeared to degrade the properties of concrete with an indication of lower compres-sive strength. However, if the dosage levels are lower than the optimum dosage, raising the admixture dosage might help enhance the con-crete characteristics. </jats:p

Investigating Behaviour of Reinforced Concrete with Glass Fibre

Concrete is the most commonly used building material. Nowadays, the world has seen the construction of engineering applications that has become difficult and complicated. Therefore, it is important to have high strength and adequate workability. Besides that, the glass fibre is highly beneficial as a construction material for reinforced concrete as it can be identified as one of the numerous compelling topics related to its benefits. This study contributes to the specification and classification of glass fibre reinforced concrete (GFRC). However, ordinary concrete has limited ductility, slight resistance to cracking, and insufficient tensile strength. Internal micro-cracks in the concrete are visible, and the proliferation of such micro-cracks caused its weak tensile strength. When a certain percentage of fibre is added to the concrete, it improves the properties of the strain, namely, resistance to cracking, ductility, toughness, and flexure strength. The current paper outlines the experimental study conducted on the usage of glass fibre with structural concrete. The parameters were used in percentages, which varied from 0.5% to 2% by weight of cement in concrete, and the properties of the FRC (fibre reinforced concrete), such as ultrasonic pulse velocity test, flexure strength, and compressive strength were examined. However, it refers to an increase in deformation before failure of the structural concrete, reinforced with a high ratio of GFR. The results show good performance of concretes containing glass fibre and increasing glass fibre content, increasing the compressive strength.</jats:p