International Conference on African Development Issues (CU-ICADI) 2015: Materials Teclmology Track Innovative Use of Momordica Angustisepala Fibers for improved strength of Recycled Concrete Anthony Nkem Ede, Oluwarotimi Michael Olofinnade, Paul Oluwaseun Awoyera Department of Civil Engineering, Covenant University, Km 10, Idiroko Road, Canaan Land anthony.ede@covenantuniversity.edu.ng. rotimi.olofinnade@covenantuniversity.edu.ng paul.awoyera@covenantuniversity.edu.ng Abstract- The consistent demands fm· natuml agg1·egate by the constmction industi·y is on the inuease and consequently cost of consti·uction is affected. The increase in demand fm· natuml 1·esom-ces fm· consti·uction and the continuous depletion of such 1·esom-ces could ueate envimnmental and sustainability issues. In the quest fo1· pmvision of affm·dable housing amund the wodd, the adoption of waste conuete matedal fm· consti·uction and in pa1-ticulai· as a 1·eplacement of agg1·egates in conuete is becoming an option. Past 1·eseai-ches showed that the sti·engths of conuete pmduced with waste concrete a1·e lower than that pmduced with natuml agg1·egates. This pape1· examines the potential of impmving sti·ength of conuete pmduced fmm 1·ecycled waste conuete as agg1·egate matedals with diffe1·ent pmpm·tions of fibe1· added to the mix. Conuete cubes of dimension 150 mm x 150 mm x 150 mm and cylindei"S we1·e cast at the Sti·uctm·es Labomto1·y of the Depa1-tment of Civil Engineel"ing, Covenant Unive1·sity, Ota, Nigeda. The cubes we1·e p1·epa1·ed by 1·eplacing the coa1·se agg1·egate of nm·mal conuete mix with 0, 20, 50, 70, and 100% of waste conuete agg1·egate. Momm·dica Angustisepala fiber (local sponge) was added in pmpm-tion of 0.25%, 0.5% 0.75%, and 1% by mass of agg1·egates. Tests conducted on both f1·esh and ha1·dened conuete include: slump test on f1·esh conuete, comp1·essive sti·ength of the conuete cubes and split tensile sti·ength of conuete cylinde1·s. Statistical methods we1·e used to analyze the test 1·esults. The test 1·esults indicated an app1·eciable inuease in sti·ength of fibe1· 1·einfoi-ced waste agg1·egate conuete. Test 1·esults show that RCA of up to 50% can be used to obtain a good conuete mix while Momm·dica Angustisepala fibe1· content of up to 0.5% can be used to impmve comp1·essive and tensile sti·ength of conc1·ete. Index Terms-- Recycled Conuete, Agg1·egates, Momm·dica Angustisepala Fibe1·s, Comp1·essive Sti·ength, Split Tensile Sti·ength. 141 I. INTRODUCTION 'According to Henry et a!. [ 1]', the construction industry represents one of the most dynamic and complex industrial sector in every nation of the world as increases in construction activities is very common. This means more and more natural resources are being depleted and more construction wastes are also being generated. Construction waste is a growing problem in many countries because of its increased burden on landfill sites operation and the consequent surface and underground pollution that accompany it. According to [2], over 15 metric tonnes of solid wastes are generated annually from construction industries in Nigeria, which include wasted sand, gravel, bitumen, bricks and masonry concrete. Globally, portions of such waste is being recycled and utilized m building materials. Therefore, concrete recycling is very important for sustainable development in current [3]. Currently in major cities within Nigeria like Lagos, there are limited land space available for development. This implies that for future development within the major city metropolis, some existing structures must be demolished and the resulting waste are cart away to dump sites since the issue of managing construction waste materials is relatively a new practice in the construction industry. According to [4 ], the generation rate of municipal solid wastes in urban areas such as Ota metropolis, Ogun State, Nigeria, have increased at a disturbing rate over the years while lack of efficient and modern technology for the waste management turns it to a big problem for the society. When added to the increasing generation of demolition waste, the total level of waste will only increase the source of soil, water and air pollution. This will go forth to aggravate the problems of low environmental awareness of the construction wastes