Abstract—Implementing significant advantages in the supply of self-compacting concrete (SCC) is necessary because of the, negative features of SCC. Examples of these features are the ductility problem along with the very high cost of its constituted materials. Silica fume with steel fiber can fix this matter by improving the ductility and decreasing the total cost of SCC by varying the cement ingredients. Many different researchers have found that there have not been enough research carried out on the steel fiber-reinforced self- compacting concrete (SFRSCC) produced with silica fume. This paper inspects both the fresh and the mechanical properties of SFRSCC with silica fume, the fresh qualities where slump flow, slump T 50 and V- funnel. While, the mechanical characteristics were the compressive strength, ultrasound pulse velocity (UPV) and elastic modulus of the concrete samples. The experimental results have proven that steel fiber can enhance the mechanical features. In addition, the silica fume within the entire hybrid mix may possibly adapt the fiber dispersion and strengthen deficits due to the fibers. It could also improve the strength plus the bond between the fiber and the matrix with a dense calcium silicate-hydrate gel in SFRSCC. The concluded result was predicted using linear mathematical models and was found to be in great agreement with the experimental results. Keywords—Self-compacting concrete, silica fume, steel fiber, fresh and mechanical properties. I. INTRODUCTION ELF–COMPACTING Concrete (SCC) is the rapid revolution in concrete production which provides a high, fresh quality as well as hardened characteristics. The SCC mix has the ability to resist segregation and to flow easily by it is own weight [1], [2]. The properties of SCC have been studied in many researches due to their importance and the ability to solve the problems of a concrete mix [2]. To develop the SCC-mix required to reduce the aggregate content with as high binder content as possible in order to maintain excellent fresh properties, it is recommended to minimize the water content and use a chemical admixture, such as superplasticizer or Glenium [3], [4]. An increase in cement content will lead to the brittleness of the concrete and increase the total cost. To avoid these two problems, steel fiber with a cement replacement material (CRM) can be used. This is because the fiber can bridge the cracks and enhance the ductility of the concrete. While, the RCM can replace part of the cement and hence, reduce the total cost [5]. Much research has been conducted to investigate the properties of fiber-reinforced self-compacting concrete (FRSCC) [6]-[8]. The disadvantages of fiber in a concrete mix are clumping. Ahmed Fathi Mohamed is PhD candidate at the department of civil engineering, Universiti Teknologi PETRONAS” (UTP) –Malaysia (H/P: 0060104616237; e-mail: alahmdy665@yahoo.com). This is because the fibers may clump together before they are added to the mix; the normal mixing action will not break down these clumps [9], [10]. Silica fume is a type of CRM that can be applied to replace the cement content in the concrete and can increase the workability properties of the SCC mix [11], [12]. Silica fume with different levels of replacement in the SCC mix have been studied to ensure the effectiveness and optimum degree of replacement that can be used [13]. The ultrasonic pulse velocity can be consider as an indicator to check the reliability of strength gain for concrete with 95% confidence limits of ±20% on the predicted strength [14]. Today’s method to measure the None Destructive Test (NDT) parameters is based on the years-old ultrasonic method. Similar combinations include other qualities of the ultrasonic measurement, such as UPV, and the damping constant [15]. Assessment of the concrete quality using the UPV test was found in literature as hardened properties of the concrete sample at different curing times [16]. The objectives of this work have been first to study the effect of steel fiber and silica fume on the properties of SFSCC. Second is to find out the relationship between the compressive strength with the ultrasonic pulse velocity (UPV) and the elastic modulus of SFSCC respectively. II. THE EXPERIMENTAL PROGRAM A. Materials and Methods ASTM, type-1 ordinary Portland cement (OPC) was applied in the experiment. Its chemical composition was tabulated and presented in Table I. Silica fume was provided by Elkem Materials in a dry densified form of Grade 920E with LOI less than 4% and a particular area (Bet) of 15-35 m 2 /gram verified with the specification of ASTM C-1240. The chemical composition of the silica fume has been proven as presented in Table I. The fine aggregate in the experiment was clean natural sand with a specific gravity of 2.61 and fineness modulus of 2.76; the largest size was only 3.35mm. Since the coarse aggregate was applied as (10-5)mm crushed granite stone according to the BS: 812-103.2-1989, a particular gravity of 2.66 in SSD was obtained. HRWR superplasticizer from SIKA- KIMIA, Malaysia was tried for the enhancement of the workability of the concrete. It is a highly effective liquid-based superplasticizer for the production of free-flowing concrete that complies with the requirements of BS 5075. WSF0220 high-strength steel fiber of the diameter of 0.2mm and 20mm in length with an aspect ratio of 100 was used in this experiment to replace the cement by weight. Its tensile Ahmed Fathi Mohamed, Nasir Shafiq, M. F. Nuruddin, Ali Elheber Effect of Silica Fume on the Properties of Steel- Fiber Reinforced Self-compacting Concrete S World Academy of Science, Engineering and Technology International Journal of Civil and Environmental Engineering Vol:7, No:10, 2013 754 International Scholarly and Scientific Research & Innovation 7(10) 2013 scholar.waset.org/1307-6892/17195 International Science Index, Civil and Environmental Engineering Vol:7, No:10, 2013 waset.org/Publication/17195