Optimum intensity of compaction in drained state consolidation of clay beams
Unavailability of aggregates, in plains of Pakistan, has compelled to find alternative economical materials of building construction. Efforts are being made to introduce Reinforced Baked Clay (RBC) panels of beams as a substitute for Reinforced Cement Concrete (RCC) to build low cost houses. However, shrinkage and reduced compressive strength of baked clay beams is an obstacle. This paper presents optimum compactive pressure to be applied to clay beams during casting to reduce shrinkage and to achieve maximum possible compressive strength. For this purpose, clay beams were cast and compacted at 0 to 7 MPa in drained state. Shrinkage of beams and compressive strength of cubes was determined. The results show that (i) shrinkage of clay beams reduced from 8 to 1.25 % at compactive pressure of 2 MPa, and 6 MPa, respectively, and (ii) the compressive strength of both the unbaked and baked clay increased by increasing compactive pressure on clay beams during casting. However, there was no significant difference in compressive strength of clay beams when compressed at pressure from 6 to 7 MPa. The compressive strength of baked clay obtained at optimum compactive pressure of 6 MPa was 35 MPa, which is about 1.7 times higher than that of M20 grade concrete.
Abdi, M.R., Parsapajouh, A. & Arjomand, M.A. 2008. Effects of random fiber inclusion on consolidation, hydraulic conductivity, swelling, shrinkage limit and desiccation cracking of clays. International Journal of Civil Engineering, 6(4):284-292.
Andrade, F.A., Al-Qureshi, H. A. & Hotza, D. 2011. Measuring the plasticity of clays: a review. Applied Clay Science, 51(1):1-7.
Ansari, A.A. & Lakho, N.A. 2013a. Determination of structural properties of baked clay as replacement of RCC. International Journal of Emerging Technology and Advanced Engineering, 3(2):17-25.
Ansari, A.A., Bhatti, N.K. & Bhutto, A. 2013b. Suitability of pre-perforated post-reinforced baked clay beam panels for low cost housing. American Journal of Civil Engineering, 1(1):6-15.
Ansari, A.A. 2008. Experimental study of the behaviour of pre-perforated post-reinforced baked clay panels of beams, Ph.D. Thesis, Quaid-e-Awam University of Engineering Science and Technology, Nawabshah.
ASTM C62-13a. 2013. Standard specification for building brick (solid masonry units made from clay or shale). ASTM International, West Conshohocken.
BIS 10262. 2009. Indian standard concrete mix proportioning - Guidelines (First revision). Bureau of India Standard, New Delhi, India.
Boivin, P., Garnier, P. & Tessier, D. 2004. Relationship between clay content, clay type, and shrinkage properties of soil samples. Soil Science Society of America Journal, 68(4):1145-1153.
BS EN 12390-3:2002. Testing hardened concrete - Part 3: Compressive strength of test specimens.
Dixon, D.A., Gray, M.N. & Thomas, A.W. 1985. A study of the compaction properties of potential clay—sand buffer mixtures for use in nuclear fuel waste disposal. Engineering geology, 21(3-4):247-255.
Douglas, J. & Ransom, B. 2007. Understanding Building Failures. Taylor & Francis.
Fatahi, B., Le, T.M., Fatahi, B. & Khabbaz, H. 2013. Shrinkage properties of soft clay treated with cement and geofibers. Geotechnical and Geological Engineering, 31(5):1421-1435.
Lakho, N.A. & Zardari, M.A. 2016a. Comparison of Compressive and Tensile Strength of Baked Clay with Those of Normal Concrete. Engineering, 8:301-307.
Lakho, N.A. & Zardari, M.A. 2016b. Flexural Behaviour of Reinforced Baked Clay Beams. Engineering, 8, 403-409.
Lakho, N.A. & Zardari, M.A. 2016c. Experimental Study of Flexural Behaviour of Reinforced Baked Clay Beams under Impact Loading. Engineering, 8:347-352.
Lakho, N.A. & Zardari, M.A. 2016d. Suitability of Large Sized Compacted Baked Clay Blocks as a Walling Material. Engineering, 8:669-675.
Lakho, N.A. & Zardari, M.A. 2016e. Effect of intensity of compaction on crushing strength of indigenous baked clay. Journal of Engineering Research, 4(2):17-28.
Lakho, N.A., Zardari, M.A. & Memon, N.A. 2015a. Reduction of Cracking and Shrinkage in Compressed Clay Beams during Drying. Mehran University Research Journal of Engineering and Technology, 35:395-400.
Lekshmi, M.S., Vishnudas, S. & Nair, D.G. 2017. An investigation on the potential of mud as sustainable building material in the context of Kerala. International Journal of Energy Technology and Policy, 13(1-2):107-122.
Nidzam, R.M., Norsalisma, I. & Kinuthia, J.M. 2016. Strength and environmental evaluation of stabilised Clay-PFA eco-friendly bricks. Construction and Building Materials, 125:964-973.
Lakho, N.A., Zardari, M.A., Memon, M. & Saand, A. 2015b. Design and fabrication of a mechanized system for casting and compacting laboratory-size clay beams. Scientia Iranica. Transaction A, Civil Engineering, 22(6), 2046-2051.
Omidi, G.H., Thomas, J.C. & Brown, K.W. 1996. Effect of desiccation cracking on the hydraulic conductivity of a compacted clay liner. Water, Air, & Soil Pollution, 89(1):91-103.
Phonphuak, N., Kanyakam, S. & Chindaprasirt, P. 2016. Utilization of waste glass to enhance physical–mechanical properties of fired clay brick. Journal of Cleaner production, 112:3057-3062.
Rhodes, D. 2015. Clay and glazes for the potter. Martino Fine Books.
Smeu, S., Gal, A. & Badea, C. 2014. Environmental friendly building materials: Unfired Clay Bricks. Journal of Environment, 3(3):47-50.
Umana, U.E., Davie, C.T. & Eminue, O. O. 2016. Investigation of the Effect of Multiple Wetting and Drying Cycles on the Shrinkage and Cracking of Engineered Clay Soil. International Journal of Engineering, 5(11): 24-35.
Walker, P.J. 1995. Strength, durability and shrinkage characteristics of cement stabilised soil blocks. Cement and Concrete Composites, 17(4):301-310.