# Introduction rick masonry is one of the oldest forms of building construction Brickwork is a composite material with bricks as the building units and the mortar as the jointing material (Freeda Christy C. et. al, 2013).The strength of the bricks-work primarily depends upon quality and strength of the brick, the type of mortar and the method of bonding adopted in construction, type of material used, nature of workmanship and supervision. Brick masonry plays a significant role in the construction industries of bangladesh where natural stones are not available and other type of building materials like concrete, MS sheets or CI sheets, and artificial materials are costly. The rapid progress over recent past in the understanding of the materials and considerable advances in the method of design have increased acceptance of load bearing masonry as a variable structural material. (S.P. Bindra, 2013). In residential buildings, roof system is a vital part. The selection of the type of material and construction is made, keeping in view the requirements of strength, water proofing, thermal insulation, fire resistance, durability and economy. It was therefore felt to investigate the local carrying capacity of different type of masonry slab. Reinforced brickwork is a typical type of construction in which the compressive strength of bricks is utilized to bear the compressive stress and steel bars are used to bear the tensile stresses in a slab. In other words the usual cement concrete is replaced by the bricks. However since the size of a brick is limited, continuously in the slab is obtained by filling the joints between the bricks by cement mortar. The reinforcing bars are embedded in the gap between the bricks which is filled with cement mortar. The designs of reinforced bricks slab are similar to these of reinforced concrete slab. (B.C. Punmia, 2012).Ahmed, T. and Junayet, A., (1996) carried out a comparison study between Ferro cement slab and conventional R.C.C. slab in terms of their flexure behavior and cost. In terms of appearance, durability and cost, brick masonry is comparatively superior to other alternatives (Hossain, M. M. et al., 1997). The main aim of this study is to investigate the mechanical properties of masonry slabreinforced with alternative materials (wire mesh and minimum reinforcement) to evaluate their performance and economy compared to conventional RCC slab. An endeavor will make to evaluate the feasibility of masonry slab to replace RCC slab. # II. # Materials and Methods # a) Specification of Materials In this study Bricks, Portland Composite Cement, Sand and Reinforcement (wire mesh and deformed bar) from the local manufactures has been used and the properties of brick and mortarare given in Table 1 From table 1, it is found that the AKIJ brand brick have maximum compressive strength. The water absorption capacity is 12.22 % which is less than 1/6 of it's own weight. AKIJ brand brick was uniform in color, size and shape is regular, campact, free from crack and other flaws such as air, bubbles, stone nodules etc. Although it's cost is maximum but don't vary too much from the other brand. So AKIJ brand brick was selected for the final work. Bashundhara cement with Khustia sand having fineness modulous of 1.65 in ratio 1:2 gives greater compressive strength. So it was selected for the final work. # b) selection of slab Two types of masonry slab reiforeced with wire mesh and minimum reinforcement and one traditional RCC slab having dimension 4ft x 2.5ft x 4.5 inch were selected for the test. # c) Design of Masonry and Rcc Slab The slabs were designed as one way slab. In case of masonry slab reinforced with wire mesh 0.5 inch spacing wire mesh was used. The bottom clear cover was 0.75 inch and top mortar layer was 0.5 inch. In masonry slab using minimum reinforcement 10 mm dia bar was used. The number of reinforcement in long direction was 5 nos and in short direction was 7 nos. Reinforcement was used only in tension zone. No shear reinforcement was used. Bottom clear cover was 0.75 inch and top mortar layer was 0.5 inch. In traditional RCC slab the number of reinforcement was kept as same as masonry slab using minimum reinforcement so that they can be compare in a similar way. Bottom clear cover was 0.75 inch. Herring bone bond pattern was used in masonry slabs. The contribution of brick in slabs thickness was 2.75 inch. In this arrangement of brick work, bricks are laid above bottom surface inclined at 45 0 in two directions from the center. Cross-section of the above mentioned slabs are shown in figure 1(a), figure 1 The load was applied by the hydraulic jack by pumping it. The reading of deflection gauge at each point was taken with respect to each small division of pressure gauge. The data were recorded untill the failure of slab. # III. # Results and Discussion a) Masonry slab using Wire mesh In masonry slab using wire mesh no deformed bar was provided. After curing for 28 days the slabs failed under load and the loads are shown in table 3. Deflection was measured at 3 points as remarked in the typical experimental setup. The masonry slab using wire mesh was found to take 9.1 kips load before failure which is equivalent to 1000 psf load. Maximum deflection is 2.1 mm at mid point. Deformed bar were used in masonry slab using minimum reinforcement. The masonry slab using minimum reinforcement carried 20 kips load before failure which is equivalent to 2000psfload. Maximum deflection was found 1.28 mm at point 2. RCC slab using minimum reinforcement took 22.59 kips load before failure which is equivalent to 2500 psf load. Maximum deflection is 3.98 mm. Figure 3 shows the variation of deflection with load for all types of slab at point 1 which is located at a distance 17 inch away from the right support. The deflection at point 1 is maximum for RCC slab, second maximum deflection was found for masonry slab using wire mesh. This is due to the elasticity of the wire mesh. Masonry slab using minimum reinforcement shows minimum deflection due to use of deformed bar and brittleness of brick. Figure 5 shows the variation of deflection with load for all types of slab at point 3 which is located at a distance 17 inch away from the left support. The minimum deflection is for masonry slab using minimum reinforcement and maximum deflection is for RCC slab. Masonry slabs failed suddenly without any advanced warning due to the brittleness of brick. There is no yield point in the figures which ensure the sudden failure of slabs. # b) Masonry slab using minimum reinforcement # c) RCC slab using minimum reinforcement # IV. Variation of Deflection at Points # V. Crack Pattern a) Masonry slab using wire mesh Figure 6 : Failure pattern of masonry slab using wire mesh The failure pattern of masonry slab using wire mesh is flexure-tension type. Failure occurred at almost midpoint. This type of failure may be initiated due to the increase of principle tensile stress greater than combined tensile stress of brick and mortar. The failure was sudden due to the brittleness of brick and the deflection was greater than masonry slab using minimum steel due to the greater elastic property of wire mesh. The crack of RCC slab using minimum steel initiated due to the flexure but the failure occurred due to the combined action of flexure and shear. This type of failure occurred due to the increase of combined flexure and shear stress greater than principle tensile stress of concrete. # b) Masonry slab using minimum reinforcement # VI. # Economy Analysis The amount of materials required in the manufacture process and the cost of three types of slab is shown in table 6 and table 7 Deviation of load carring capacity of masonry slabs using wire mesh and minimum reinforcement from RCC slab are 60.11% and 11.46% respectively; deflections are 47.24% and 67.84% respectively; flexural stresses are 60.25% and 20.70% respectively and costs are 24.14% and 2.85% respectively. The deviation of performance and costs of masonry slabs from RCC slab in shown in the following bar diagrams. ? Deviation of load carring capacity of masonry slabs using wire mesh and minimum reinforcement from RCC slab are 60.11% and 11.46% respectively; deflections are 47.24% and 67.84% respectively; costs are 24.14% and 2.85% respectively. ? Masonry slabs failed due to brick failure without any advanced warning. The crack pattern of RCC slab, masonry slab using wire mesh and minimum reinforcment are flexure-shear, flexure-tension and flexure-shear respectively. ? Masonry slab using wire mesh can be used in case of small span slab, restricted roof and waffle slab system. For long span slab and higher tension, masonry slab using minimum steel or RCC slab can be used. As the cost of RCC slab is only 2.85% greater than the masonry slab using minimum steel, so RCC slab is preferable for higher tension. But in case of architectural appearance and deflection restriction, masonry slab using wire mesh can be used. ![(b), and figure 1(c) respectively. Experimental Investigation of Unreinforced and Reinforced Masonry Slab Global Journal of Researches in Engineering ( ) Volume XVI Issue II Version I d) Casting, Curing and Testing of Slabs Three types of slabs were casted according to the design specified above and cured for 28 days. After curing the slabs were tested in the laboratory. The typical and laboratory experimental setups are shown in figure 2(a) and figure 2(b) respectively.](image-2.png "") 2![Figure 2(a) : Typical Experimental setup for two point load test.Figure 2(b) : Laboratory Experimental setup.](image-3.png "Figure 2 (") 2![Figure 2(a) : Typical Experimental setup for two point load test.Figure 2(b) : Laboratory Experimental setup.](image-4.png "Figure 2 (") 3![Figure 3 : Variation of Deflection (inch) with Load (Kip) at Point 1](image-5.png "Figure 3 :") 4245![Figure 4 : Variation of Deflection (inch) with Load (Kip) at Point 2 Figure 4 shows the variation of deflection with load for all types of slab at point 2 which is located at the midpoint of the slab. All slabs show maximum deflection at point 2. Maximum deflection is 3.98 mm for RCC slab.](image-6.png "Figure 4 : 2 Figure 4 Figure 5 :") 78![Figure 7 : Failure pattern of masonry slab using minimum reinforcement](image-7.png "ExperimentalFigure 7 :Figure 8 :") ![Figure 9(a) : Deviation of load capacity Figure 9(b) : Deviation of Deflection](image-8.png "?") ![](image-9.png "") 1Mahmudul Hasan Mizan ? & Mishuk Majumder ?Year 20167Bmaterial.( ) Volume XVI Issue II Version I E of Researches in EngineeringGlobal Journal© 2016 Global Journals Inc. (US) 2AgeRatio (1:2)Average Compressive Strength (psi)Cement : Kushtia Sand29503 daysCement : Sylhet Sand3125Cement : Sylhet + Kushtia Sand3045Cement : Kushtia Sand37907 daysCement : Sylhet Sand3750Cement : Sylhet + Kushtia Sand3630 3Observed Pressure gauge ValueLoad (kN)Load (kip)At Point1 Deflection (mm) (in)At Point 2 Deflection (mm) (in)At Point 3 Deflection (mm) (in)000000000115.83.550.0150.000590.150.00590550.0210.000822224.940.0190.000740.2650.01043310.0340.001333286.290.0480.001880.50.0196850.0550.002164347.640.20.007871.60.06299210.1680.00661540.19.010.6170.024292.10.08267720.4750.01870 4Year 20169of Researches in Engineering ( ) Volume XVI Issue II Version I EGlobal Journal 5Observed Pressure gauge ValueLoad (kN)Load (kip)At Point1 DeflectionAt Point 2 DeflectionAt Point 3 Deflection(mm)(in)(mm)(in)(mm)(in)000000000115.83.550.030.000980.540.021250.0370.001452224.940.040.001730.960.037790.0630.002483286.290.080.003141.40.055110.1250.004924347.640.190.007401.850.072830.2050.00807540.19.010.270.010622.50.098420.290.01141646.110.360.360.014172.80.110230.3720.01464752.2511.740.460.018112.950.116140.4650.01830858.4513.140.590.023223.10.122040.580.02283964.1514.420.710.028033.220.126770.790.031101070.2515.790.890.034843.40.133850.840.033071176.717.240.950.037403.680.1448811.0050.03956128318.650.990.038973.850.151571.250.04921138920.001.020.040153.880.152751.3050.05137149521.351.090.042913.910.153931.3980.0550315100.522.591.290.050783.980.156691.4350.05649 6Masonry slabspecificationswith minimumRCCwith wire meshreinforcementCement (kg)171919Fine Aggregate [1] (cft)0.9241.061.2Fine Aggregate [2] (cft)0.0130.013-Coarse Aggregate (cft)--1.8Steel (kg)-6.56.5Brick (nos)3131-Wire mesh(sft)7.9--Brick work (cft)2.292.290Casting (cft)003.75Plastering (sft)10100Fabrication of steel (kg)26.56.5 7Cost (tk)specificationsunit cost (tk)with wire meshWith minimum reinforcementRCC slabCement (kg)8.3141.1157.7157.7Fine aggregate [1] (cft)6055.4463.673.2Fine aggregate [2] (cft)350.4550.4550Coarse aggregate (cft)16000292.8Steel (ft)550357.5357.5Brick (nos)82482480Experimental Investigation of Unreinforced and Reinforced Masonry Slab Global Journal of Researches in Engineering ( ) Volume XVI Issue II Version I VII. Deviation of Performance and Cost of Slabs © 2016 Global Journals Inc. (US) © 2016 Global Journals Inc. (US)References Références Referencias * Experimental Study on Axial compressive Strength and Elastic Modulus of the Clay and Fly Ash Brick Masonry FreedaChristy C* TensingD MercyShanthi R Journal of Civil Engineering and Construction Technology 4 4 2013 * SPBindra SPArora A Text Book Building Construction New Delhi Dhanpat Rai Publication 2013 5th Edition * BCPunmia KJAshok KJArun A Text Book of Building Construction New Delhi Laxmi Publications LTD 2012 20th Edition * MMHossain SSAli AMRahman Properties of Masonry Constituents Bangladesh 1997 25 IEB * AThohid JAbu Low Cost Building 1996 Khulna University of Engineering and Technology, Bangladesh. Experimental Investigation of Unreinforced and Reinforced Masonry Slab Undergraduate Thesis