VOL. 12, NO. 9, MAY 2017 ISSN 1819-6608 ARPN Journal of Engineering and Applied Sciences © 2006-2017 Asian Research Publishing Network (ARPN). All rights reserved. www.arpnjournals.com 2854 UTILIZATION OF RICE HUSK ASH AND CERAMIC WASTES IN MANUFACTURING OF DEVELOPED CEMENT BRICKS Azza I. Hafez, Maaly M. A. Khedr, Mona S. Mohammed, Rania M. Sabry and Randa M. Osman Department of Chemical Engineering and Pilot Plant, National Research Centre, Cairo, Egypt E-Mailranda.osman@yahoo.com ABSTRACT Huge quantity of rice husk ash (RHA) and broken ceramics in Egypt are produced as wastes and become of great threat to the environment, causing damage to the land and the surrounding areas in which it is dumped. In addition, production of cement is responsible for about 7% of all CO2 generated in the world. For that, the aim of the present research is to produce modified cement bricks by replacing cement partially by RHA and broken ceramic wastes, to bring a substantial reduction for CO2 emitted every year in the atmosphere, and to reuse agricultural and industrial solid wastes. Therefore two sets of experiments were investigated by replacing part of Ordinary Portland Cement (OPC) with: 1) RHA and 2) mixture of RHA and ceramic wastes, to produce modified cement bricks, at different curing time, namely7,14 and 28 days. Characterizations of raw materials used for the target preparation were carried out covering: free silica and organic matters, XRD, TGA, and DTA. The cold and boiling water absorption, compressive strength, apparent porosity and bulk density for the prepared modified concrete samples are determined. The experimental results proved that the , modified cement brick contains 5% RHA and 3% ceramic powder as cement replacement shows higher bulk density and compressive strength compared to other brick samples. The bulk density and the compressive strength were 2.33gm/cm 3 and 295 kg/cm 2 respectively, which are higher than the allowable standard limits. In addition, preliminary production cost was estimated. Keyword: ash, rice husk, brick, cement, compressive strength, ceramic waste. 1. INTRODUCTION Bricks have been a major construction and building material for a long time. The worldwide annual production of bricks in 2015is about 1500 billion units and the annual demand for bricks is expected to be continuously rising by 5-6% [1,2]. Ordinary Portland cement (OPC) is a conventional brick, composed of cement and sand. It is very similar to concrete, except that the aggregate materials used are much finer. It is well known that the production of OPC is highly energy intensive and releases significant amount of greenhouse gases [3]. Production of 1 kg of OPC consumes approximately 1.5 kwh of energy and releases about 1 kg of CO2 to the atmosphere. Worldwide, production of OPC is responsible for about 7% of all CO2 generated [4]. For environmental protection and sustainable development, many researchers have studied utilization of waste materials to produce bricks [5-9].On the other hand, over one million acres of rice crops were cultivated in Egypt, where one acre of rice produces 1.6 million tons of husks after the harvest in October and November, which are burned in open field, where uncontrolled combustion contributes to enormous environmental threats lowering theair quality in the involved area [10-14]. In addition, the disposal of large bulk of rice husk ash (RHA) has gain serious concerns due to the importance of preserving a clean environment in the present days. The utilization of this waste reduces the negative effects of its disposal, as well as energy consumption and CO2 emission. In addition, it would be more profitable to utilize a priceless waste while simultaneously minimizing pollution. For that, the objective of the present work is to study the possibility of reusing RHA in the manufacture of environmentally saved low cost developed cement bricks. 2. MATERIALS AND METHODS 2.1. Raw materials Four types of raw materials are used in the experimental work:1) OPC obtained from Portland cement company in Cairo, Egypt,2) rice husk (RH) obtained from local paddy mill rice in Egypt, 3) broken ceramic wastes and 4) commercially available stone chips and sand as coarse and fine aggregates. 2.2. Experimental procedureand analyses Two groups of experiments were investigated by replacement part of cement by: 1) RHA and 2) RHA and ceramic wastes, to form modified cement bricks 2.2.1. Preparation and characterization of cement /RHA bricks RHA was burnt at different temperatures (400 o C to 800 o C) to obtain ash via muffle furnace. Itwas used as a partial replacement of cement material in weight percentage starting from 0 % till 20 %, increasing by 5 %.Five mixtures were prepared, each mixture ratio was 1: 2: 4 (cement blend: fine (sand): coarse aggregates (stone chips). The cement blend consists of a pre-determined mixture of cement, RHA, and broken ceramics. The results were compared with a control mixture consisted of the same constituents with the same ratios except the absence of RHA and ceramics. All combinations were mixed together for five minutes before the addition of water to obtain a homogenous mixture. Potable tap water was used for mixing and curing the cement bricks. The blend was then casted into cubic molds of approximate dimensions 50x50x50 mm 3 . To minimize segregation, all the mixtures were compacted by hand tamping, compaction wascarried