By POPOOLA, Olorunnisola Hannah (08/30GB078) Department of Civil Engineering, University of Ilorin. Project Supervisor: Dr. S.A. RAJI JUNE, 2013

INTRODUCTION In the world today, concrete is the most widely used construction material whose functions cannot be over emphasized, some reasons being for its simplicity, ease in availability, low cost of ingredients etc.(Islam et al, 2011). The needs of the construction industry for a better concrete with improved properties led to improvements on the concrete by addition of certain admixtures like the reprocessed polyethylene, glass, Polymer concrete which is a composite material is formed by the combination of mineral aggregate such as sand, gravel with monomers.

AIM & OBJECTIVES The aim of this project is to improve the properties of concrete and produce concrete that are of less density, reduced permeability and resistant to corrosion by obtaining results of reprocessed polyethylene ‘PWS’ composite concrete, modelling the problem using MIDAS Engineering software and comparing the outcome with known benchmark results.

SCOPE OF STUDY The scope of this project involved obtaining properties of laboratory model of reprocessed polyethylene pure water sachet ‘PWS’ composite concrete, developing a mini Visual basic program for analysis of rectangular tanks & Computer modelling and analysis of a concrete septic tank of standard dimension using the MIDAS Engineering software.

METHODOLOGY Methods employed in this study include the following: Review of laboratory research Manual calculations Development of mini VB program. Modelling and analysis using Midas Engineering software..

Modelling & Analysis stages

RESULT & DISCUSSION Assume 150 students reside in a typical University of Ilorin hostel Total capacity=180N = 29000litres Internal dimension=5.08 * 2.54 *1.5m To check for stability: Sliding; Frictional resisting force sliding force µ (1.0P w + 1.0P b ) ¥ f H K Overturning; Frictional resisting moment overturning moment CASE 1: TANK EMPTY Frictional resisting force =22.36kN Sliding force=14.30kN Frictional resisting moment = 91.32kNm Overturning moment=11.18kNm CASE 2: TANK HALF-FULL Frictional resisting force = 30.77kN Sliding force=14.33kN Frictional resisting moment= 115kNm Overturning moment=11.18kNm CASE 3: TANK FULL Frictional resisting force = 35.81kN Sliding force=14.30kN Frictional resisting moment = kNm. Overturning moment=11.18kNm Hence the structure is stable

RESULTS DISCUSSION Roof Slab Design Depth=177mm Loading Self weight of slab= 0.25*24 = 6.00kN/m 2 Finishes say = 1.00kN/m 2 Total dead load gk = 7.00kN/m 2 Surcharge (vehicle) =10kN/m 2 Live load due to partial access on roof =0.75kN/m 2 Total live load qk =10.75kN/m 2 Ultimate design load, n=27kN/m Moment=29.14kNm K=0.037 Z=225mm As=323.96mm 2 /m Provide c/c (As prov=393mm 2 /m) Results above showed that mass concrete was used for wall of septic tank instead of block work, this is because of the need to model the concrete material using polymer concrete. In the calculations, concrete wall thickness = 400mm, height of wall =1500, floor thickness=500mm and half of the section of the tank was considered in determining the stability of the tank. Also is the roof slab designed as one way spanning using 10mm reinforcement.

CONCLUSION & RECOMMENDATION CONCLUSION Based on review of past Laboratory research it may be concluded that the compressive strength of polymer concrete is low as compared with concrete but it increases with curing age. Also, it may be concluded that computer application greatly increases speed, accuracy and reliability of civil engineering design calculations. RECOMMENDATION It is recommended that further research to test for the strength of polymer concrete by the addition of iron chippings should be considered so as to compare the outcome with the strength of plain concrete. It is also recommended that further work on the VB program RecTank (version 1.0) be done by considering design and detailing. Midas Gen Engineering software being newly introduced in Nigeria should be encouraged for application Civil engineering project works.

REFERENCES Bhutta, A.M and Ohama, Y. (2010). Recent Status of Research and Development of Concrete-Polymer Composites in Japan. Concrete research letter, vol 1(4), pp Farkas, G. and Nemeth, O. I. (2011). Experimental polymer concrete’s mechanical properties. Proceedings of 15 th international conference on civil Engineering & Architecture, Hungary pp Islam, M.A. Rahman, M.M. and Ahmed, M. (2011), Polymer-modified Concrete: World Experience and Potential for Bangladesh, Indian Concrete Journal, pp Iyiola T.M (2008), Effect of reprocessed polyethylene “pure water sachet” on the flexural strength of polymer cement concrete beams. An unpublished B.Eng. thesis submitted to Civil Engineering Department, University of Ilorin, Ilorin, Nigeria. Lang, G. and Meyer, A. (2005). Case histories of polymer concrete applications in the U.S: pipes, manholes, structures, Conference of North American society for trenchless technology(NASTT), Orlando Florida. Mosley,W.H. and Bungey,J.H. (1999). Reinforced concrete design. 5 th ed. Macmillian press, London.