Production Of Bricks From Waste Materials – A Review

Bricks are broadly used construction and building material everywhere the world. Bricks are made from clay, but in areas where clay is not found, there we can find other sources to make the bricks. This paper presents to use the waste material to make bricks, which will reduce the waste somehow. The marketable manufacture of the bricks made from the waste material is still limited because of slow acceptance of bricks made of waste material. The bricks made from clay need kiln fire high temperature which causes to release greenhouse gasses, but the bricks made from the waste material not only reduces these risks but also reduces the waste material. This research is based on three categories based upon the methods by which bricks are made from waste materials: firing, cementing and geo polymerization. The production of bricks from waste material(s) by using kiln fire as traditional methods.

The advantage of this method is that this method utilizes waste material by replacing some or entire clay. This method utilizes 77 to 100% hematite tailings, 0 to 8% class F fly ash, and 0–15% clay. To determine the strength, water absorption and bulk density of bricks different conditions were applied, the best results were at the ratio of tailings: fly ash: clay 84:6:10. By producing the bricks with high percentages class F fly ash to replace clay at high quantity had high compressive strength, low water absorption, no cracking due to lime and resistance to frost-melting. The bricks produced from fly ash (FlashBricks) were about 28% lighter than clay bricks, improved performance parameters and had 40MPa compressive strength. The brick made from granite sawing wastes as different raw material in the production of ceramic bricks and tiles, the results showed that the granite sawing waste could be used to somewhat replace the conventional raw materials.

The municipal solid waste incinerator (MSWI) slag were also tested in the brick, the results indicated that the increasing amount of the MSWI slag effect in a decrease in the water absorption rate and the compressive strength were also increased. The bricks made by the mixing of different amount of gold mill tailings with black cotton or red soils, this showed great result in terms of compressive strength, water absorption and linear shrinkage. The bricks made using kaolin fine quarry residue (KFQR) combined with granulated blast-furnace slag (GBFS) and granite-basalt fine quarry residue (GBFQR), showed the most satisfying properties that meet the Egyptian standard specification (ESS) requirements. For the production of porous and light weight bricks with reduced thermal conductivity, of the earthenware bricks by the addition of paper processing residues as an additive. The results were according to the expectation, that the paper producing waste could be used together with brick raw materials to have the porous and light weight bricks with reduced thermal conductivity and acceptable compressive strength.

Another waste cigarette butts (CBs) were tried to make the bricks after processing, the results indicated that cigarette butts could be used in the manufacturing of light fired bricks. The bricks made using clay-sand mixed with the rice husk ash resulted in increased compressive strength and these bricks could be used in load bearing walls. The petroleum effluent treatment plant sludge were utilized in preparing environmental friendly masonry bricks in a commercial brick plant, the sludge reduced the requirements of process water and fuel. The craft pulp production residues were also used in clay bricks, after testing different properties of brick made of craft pulp residues it showed that it can be used in pore forming agent. The processed waste tea (PWT) with clay was used to make bricks, the result shoed that the PWT can be used in fired and unfired brick production with the advantage of low cost and environmental protection. The polluted river sediments were used in the brick formation after treatment in a full scale industrial brick factory experiment, this resulted in significant increase in a compressive strength and decreased porosity and water absorption.

The green and core foundry sand mixed with clay were used to produce the brick, the results were enhanced physical properties while the mineralogy was not significantly affected. The waste marble dust was used as an additive material in the industrial brick, the amount of the marble dust had positive effect on the physical, chemical and mechanical properties of the brick. The sugarcane bagasse ash waste used as a raw material for the clay brick production, by testing the brick made from sugar cane bagasse waste, it specifies that the sugar cane bagasse ash waste can be used as a filler in clay bricks.Another method which instead of using kiln firing it relies on cementing from the waste material itself or other added cementing materials. A researcher used gold mill tailings mixed with OPC in different proportions, this research shows that the cement tailings bricks would be uneconomical as compared to soil bricks. A byproduct of the iron and steel industry that is granulated blast furnace slag were used to make brick, this granulated blast furnace slag were mixed with hydrated lime and Badarpur sand. The brick made of slag lime mixture were tested and had compressive strength, bulk density and water absorption properties. The bricks and hollow blocks made using class F fly ash together with calcined phosphogypsum and mineral lime, were cured in an aggressive environment of sulfate solution. The result were seemed that these bricks and hollow blocks had sufficient strength for their use in low cost housing development. The bricks made from copper tailings mixed with different amounts of OPC. The result showed that the produced copper mine tailings cement bricks satisfied the compressive strength and water absorption necessities as recommended in Indian Standard (IS).

The wood saw dust waste (WSW) and limestone Powder Waste (LPW) combined together with Portland cement were used to make light weight bricks. The results showed that the increased level of WSW and LPW led to high energy absorption capacity, reduced weight and smoother surface compared to regular concrete bricks. The cotton waste (CW) and limestone mixed with Portland cement also produced light weight bricks as WSW and LPW. The waste glass powder (WGP) and limestone mixed with small amount of Portland cement The results indicated that the WGP used in LPW unusually improved the compressive strength, flexural strength, modulus of elasticity, abrasion resistance, freezing–thawing resistance, and thermal conductivity of LPW bricks. The brick with improved thermal resistance is made by the use of crumb rubber partially replaced sand aggregate. The high level replacements also improves other parameters of bricks. The use of stockpiled circulating fluidized bed combustion ash (SCFBCA) with OPC, lime, class F fly ash, and (or) calcium chloride resulted in compacted bricks. The masonry blocks made of limestone powder (LP) and class C fly ash (FA), without using Portland cement were tested and the results indicate that masonry blocks could be made using LP, FA and water without cement. The bricks made of coal combustion residues (CCRs) together with cement, lateritic clay soil and sand, showed good mechanical strength, low weight and is safe to health.

Other methods described above uses waste materials using high temperature or relying on cementing which also needs lots of heat. So this method is more safe as compare to two described above, which produces bricks using waste material by polymerization. Geopolymerization is a technology that depends on the chemical reactions in a high alkaline solution of amorphous silica and alumina rich solids at slightly raised temperature which forms amorphous to semi crystalline aluminosilicate inorganic polymer. Aluminosilicate inorganic polymer or geopolymer has three dimensional structures. The general formula of geopolymer is Geopolymer provides performance as compared to OPC in many application and also has additional advantages, which includes abundant raw material resources, quick progress of mechanical strength, good durability and other parameters improved than other two methods. The geopolymer bricks produced using fly ash and bottom ash with the alkali sodium silicate solution as alkali activator, resulted in concrete like building materials.

Other waste product class F fly ash were utilized with sodium silicate and sodium hydroxide solution, that sample resulted in the geopolymer brick had compressive strength between 5 and 60 MPa. Many researches have been done on many waste materials like fly ash, rice husk ash and others to produce bricks by using different methods and different proportions of the waste materials. Although many researches have been made to use waste materials but the commercial production and application of these bricks is still very low. The bricks made by firing is similar to the conventional clay method so this method can easily be applied commercially. But this method uses lots of heat and releases greenhouse gasses. Another method which is by cementing which is based on hydration reactions to strength. We can use waste material as cementing material itself or other cementing material(s). The cementing method also uses cement which uses lots of heat and releases greenhouse gasses.

The third method which is much safe to environment is geopolymerization. Geopolymerization is much better than conventional methods, this technology is relatively new. The geopolymerization consumes much less heat and releases much less greenhouse gasses. The geopolymerization has favorable physical, chemical, and mechanical properties, however it consumes extra cost on using of alkali solutions.