Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Bond strength

Effect of Addition Carbon And Glass Fibers On Bond Strength of Steel Reinforcement and Normal Concrete

Rana Hashim Ghedan

Engineering and Technology Journal, 2013, Volume 31, Issue 1, Pages 81-97

The concept of composite materials using fibers as reinforcement is not new. The aim of composing materials is to improve some properties of the original materials. In civil engineering, fiber reinforced concrete was one of the topics of interest. Using fibrous concrete in reinforced concrete structures arises a question of how does it affect the bond strength between the concrete and reinforcing steel bars. Thus, the present experimental study are carried out to have a clear understanding of the bond strength between normal concrete with two selected types of fibers which were carbon and glass fiber and steel reinforcing bars. Forty five pullout cubic specimens of size 150mm were fabricated and tested to serve that purpose. They were divided into five groups to study the effect of some selected parameters such as, type of fiber (carbon and glass),reinforcing bar diameter(12mm,16mm and 20mm)and fiber to cement ratio(f/c) by weight(0.75% and 1% ). Also, three concrete cubes having the same size of the pullout specimens from each concrete mix were tested in compression to find their compressive strength. It was found that the addition of glass fiber with bar diameter=16mm has much effect in enhancing bond strength than that enhancement accrued by addition of carbon fiber, the bond strength increases by about 13.6 % and 4.5 % with the addition of 0.75% and 1% glass fiber. On the other hand, the bond strength increases as bar diameter decreases.The addition of the carbon or glass fibers increases the bond strength for specimens with smaller bar diameter and vice versa and the fiber(either glass or carbon) to cement ratio of 0.75% give higher bond strength than that of 1.0%.

Bond Strength Assessment for Different Types of Repair Materials

Aseel S. Mansi

Engineering and Technology Journal, 2010, Volume 28, Issue 21, Pages 6325-6336

The main objective of this work is to evaluate the bond strength for
different types of repair materials. Three test methods; slant shear, splitting prism and Bi-Surface shear test with conventional and two polymer modified repair mortars were used, The conventional mortar (MC), polymer modified mortar (MSBR) was prepared by admixing SBR 15% of cement weight, polymer modified and fiber reinforced repair mortar named commercially Cempatch S (MCS) was prepared by mix Cempatch S with a water ratio of 0.2. The results show that the use of SBR and Cempatch S improves the bond strength of repair mortar compared with conventional repair mortar but the percentage increased with Cempatch S was greater than SBR. The percentage increase in bond strength for concrete substrate repaired with Mcs (CMcs) were 52.67, 174.8, and 46.7% for Slant Shear, Splitting Prism and Bi-Surface shear test
respectively relative to the corresponding repaired with conventional mortar MC(CMC); while, the corresponding percentages increase for concrete substrate repaired with MSBR (CMSBR) was 45.13, 129 and 30%. It is found that the bond strengths obtained from some tests was up to an average of four times larger than those obtained from others.