IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 _______________________________________________________________________________________ Volume: 04 Issue: 11 | Nov -2015, Available @ http://www.ijret.org 31 STUDIES ON REINFORCED HOLLOW CONCRETE BLOCK MASONRY Madan Kumar L 1 , S. Raghunath 2 1 Assistant Professor, Department of Civil Engineering, JIT Davangere, Karnataka, India 2 Professor, Department of Civil Engineering, B.M.S.C.E Bengaluru-19, Karnataka, India Abstract Masonry may be defined as the assemblage of building units joined with the help of cementitious material or any accepted joining material to perform required function. It has its own reputation and performs multi-functions in load bearing structures such as- supporting loads, dividing spaces, thermal and acoustic insulation, weather and fire protection etc, but it has to be provided separately in framed structures. In present scenario, there is a great demand for construction of Multi-storied residential buildings in urban area because of needful requirements. Most of such buildings are constructed using RC-framed structure. On the other hand RC-framed structures are expensive and relatively difficult to construct because of the need for formwork. Masonry has a great benefit since it does not need form work. If moderate to High strength Engineered hollow concrete blocks are available, one can think of providing reinforcement through the core of such Hollow blocks. In this project an attempt has been made to obtain the load carrying capacity of Reinforced Hollow Concrete Block Masonry through experimental investigation by considering two different percentages of steels - for this totally four number of Reinforced hollow concrete block masonry prisms (RHCBM) using 12 mm diameter bar and six number of Reinforced hollow concrete block masonry prisms (RHCBM) using 8 mm diameter bar were casted and tested. Further, an attempt has been made to compare the experimental load carrying capacity with the conventional mechanics based approach used for analyzing short columns. There was a fairly good co- relation between the analysis and experiments. Key Words: Unreinforced Masonry, Reinforced Hollow Concrete Block Masonry. --------------------------------------------------------------------***---------------------------------------------------------------------- 1. INTRODUCTION Masonry may be defined as the assemblage of building units joined with the help of cementitious material or any accepted joining material to perform required function. Based on structural perspective masonry can be classified into two types- Plain masonry and Reinforced masonry. Plain masonry is one where the building units are bonded (or joined) with the help of cementitious material or any accepted joining material without any reinforcements. And, this type of masonry gives little tensile strength- hence it cannot be used in horizontal spanning members like beams, slabs and also for column where it is subjected tensile stresses due to eccentric loading. Similarly, reinforced masonry is type masonry where reinforcements are used in addition to plain masonry to improve its strength in both tension and compression. 2. METHODOLOGY The Methodology adopted is conventional tests on a. Unreinforced HCB b. Reinforced Hollow Concrete Block Masonry. Two different percentages of reinforcement were tried prior to experiments on RHCBM, all the basic properties of Hollow concrete block, Mortar and Concrete was evaluated. 3. EXPERIMENTAL INVESTIGATION In present investigation the prism specimens and masonry triplets were casted using hollow concrete block of dimension 400×150×200 mm for Compressive test and Shear test respectively. Fe-415 steel of diameter 12 mm and 8 mm were taken for reinforcement in RHCBM and 53 grade of ordinary Portland cement was used in all cases. The cement mortar 1:4 with w/c ratio 0.7 (obtained by Flow table test) was adopted. M20 grade concrete has been used for filling the cells of block in RHCBM. Totally four number of Reinforced hollow concrete block masonry prisms (RHCBM) using 12 mm diameter bar , six number of RHCBM using 8 mm diameter bar and three number of unreinforced masonry prisms were casted for Compression test. Similarly, three number of masonry triplets in two sets were casted and tested for two different normal stresses to evaluate the behavior of Shear Strength. Fig -1: Prism Specimen after casting