Study of Using of Recycled Brick Waste ( RBW ) to produce Environmental Friendly Concrete : A Review

Several million tons of solid waste are produced each year due to construction and demolition activities worldwide, and brick waste is one of the widest wastes. Recently, a growing number of studies have been conducted on using recycling brick waste (RBW) to produce environmentally friendly concrete. The use of brick waste (BW) as potential partial cement or aggregate replacement materials is summarized in this review, where the performance is discussed in the form of the mechanical strength and properties related to the durability of concrete. It was found that, because of the pozzolanic activity of clay brick powder, it can be utilized as a cement substitute in replacement levels up to 10%. Whereas for natural coarse aggregate, recycled aggregate can be used instead of it, but at a limited replacement level. Concrete manufacturing from recycled aggregate can give adequate strength and can be suitable for producing medium or low strength concrete. On the other side, the utilization of fine recycled brick waste as aggregate in concrete manufacturing provides development of the properties of concrete. It develops the durability of concrete in some cases when used with replacement level up to 10% by the weight of fine aggregate.


INTRODUCTION
Concrete is the common undisputable and necessary material that is used in the creation of infrastructure all over the world. It is one of the oldest and most popularly used building materials in the world today. It is considered inexpensive, strong, easily obtainable. In addition, it is a durable material. In several laboratories, many kinds of concrete (High Volume Fly Ash Concrete (HVFAC), High Strength Concrete (HSC), High performance Concrete (HPC), Fiber Reinforced Concrete (FRC), and others ) were investigated and taken to the field to meet the particular needs. On the other hand, the manufacturing of concrete causes environmental pollution and consumption of a non-renewable resource, for example, natural aggregate. Annually, concrete manufacturing is projected as 11 billion metric tons, of which 70 percent to 75 percent is aggregate; water is 15 percent; whereas for the cementitious binder is 10 percent to 15 percent (Mobili et al., 2018; Rani and Jenifer, 2016). Portland cement clinker is considered the most widely cementitious binder utilized in concrete, but its manufacture is energy intensive (Rani and Jenifer 2016). The manufacture of one ton of Portland cement clinker releases around 850 Kg of CO2 into the atmosphere (Swaroop et al., 2015). At the same time, a huge amount of construction and demolition (C and D) waste is created. Traditionally, construction and demolition (C and D) waste are used as landfills, resulting in land resource occupation, pollution of the environment. There is an increasing need to use renewable resources instead of non-renewable resources (Guo et al., 2018; Pedro, 2017). The use of waste materials in construction materials could reduce the environmental effects of cement and concrete production. Selective demolition is one of the major assumptions for the utilization of recycled construction and demolition (C and D), which means very careful sorting for the materials during the demolition work (Pacheco Torgal and Jalali, 2011). That could lead to high quality materials for input to the recycling process and for secondary raw materials, and this can be used for new applications as a substitute for main raw materials (Pavlů, 2018). Also, the utilization of construction waste prevents the accumulation of concrete of old building waste that needs to be taken away or transported to the dumping land of solid waste. Furthermore, the cost of transportation fuel for it. The accumulation of these waste solids has caused changes in the landscape architecture, which happens by modifying the morphology of the topography of the waste material receiving area (Martínez et al., 2015).

WASTE BRICK IN CONCRETE
Brick is considered the second most common building material after concrete, and if there is damage occurs during its production, construction, and demolition activities. It is regarded as C and D waste. The ability to recycle the brick waste in the manufacture of the concrete is considered an environmentally friendly substitutional. That solution will not only decrease the problem of its disposal and moreover helps to minimize the consumption of natural materials. In addition, brick production does not involve the use of chemicals, so it considers safe and stable construction materials (Wong,2018).
The durability and the mechanical properties of concrete using the brick waste (CBW) as fine cement aggregate or coarse aggregate are summarizing below:-

Utilization Waste Brick Powder (WBP) in Concrete:-
The existence of pozzolanic is one of the necessary criteria for products that are used as a substitute for cement. amount of (SiO pozzolanic materials. This classification is according to the requirement of (ASTM618) (Olofinnade, 2016). As shown in Table 1, the sum of silicon, ferric, and aluminium oxide of WBP exceeded 70 percent , which proved that WBP had high pozzolanic activity; these components will facilitate the creation of C-S-H (calcium-sulfate-hydrogen) hydrates of silicates) or C-A-H (calcium aluminate hydrates) and thus influenced mortar and concrete performance. .
Pozzolanic brick activity results from converting crystalline structures of clay silicates to amorphous compounds during brick processing, where the clay is exposed to high temperatures between (600 ° -1000 °) C. The microstructure characterization can verify the pozzolanic activity of (WBP). (Ahmed et al., 2019; Aliabdo et al., 2014). They investigated the pore structure of paste specimens with CBP. They discovered that the pozzolanic reactivity of CBP and possibly the rehydration of unhydrated cement particles in attached mortar enhanced the density of the matrix refined the pore structure. Waste brick powder (WBP) will also help to work as a filler, minimizing the effect of the phenomenon of greater shrinkage (Zhu, and Zhu Z., 2020). And its special gravity (S.G) is greater than the other concrete materials; it helps to increase the density of concrete, resulting in highly compact and less porous concrete. As a result, by using less quantity of cement, higher strength concrete mix can be obtained, which indirectly lower the primary overhead cost (m3) of concrete, and it is considered an environmentally friendly concrete (EFC) because it eliminates the accumulation of waste of the demolished brick by consuming it (Rani and Jenifer, 2016). Several researches show that waste brick powder (WBP) can be used in concrete as a partial substitute for cement; Table 2 summarizes some of these previous researches. 0%, 5%, 10%,15%  The compressive strength is improved by replacement of brick powder (BP) to a percentage less than 10% by weight at all ages, but it starts to decrease at 15% replacing but it still more than reference mix Figure1.  Steel potential was (-265 mV) at 150 days for specimens of 10% replacement level, which was lower than reference concrete (-338 mV). Following that, it started to fluctuate and appeared to shift to a more negative potential.  After 300 days of exposure, the average potential in reference concrete was -356 mV, while the average potential in brick concrete was (-337mV). This behaviour could be explained by the better adsorptive capacity, which results in a barrier film that is difficult to break or penetrate by the corrosive chloride ions, and the pozzolanic reaction decreases the porosity and permeability of cement paste, making it stronger and more durable, Figure 2.  Water absorption for 10% brick waste was less than that of reference concrete at all curing ages, and it also decreased as curing ages increased from 150 to 240 days. At 240 days, the maximum reduction in water absorption was 13.87 % when compared to reference concrete. This decreasing is attributed to the pozzolanic reaction of brick waste, which can refine pore structures and decrease connectivity. Water transport is governed by factors such as pore connectivity and pore size distribution.  At age 150 days, water penetration depth was less than that of reference concrete for 10% replacement brick waste because the incorporation of brick waste as a replacement for cement content may improve the pore structure in the transition zone, so it decreasing the water permeability.   W/C = 0.41-0.51  1.

Utilization of Waste Brick in Concrete as Aggregate
The quality and properties of recycled brick aggregate are mainly responsible for the possibilities of using it in concrete. The major difficulties of using RBA are its high absorption of water, which has a negative effect on the workability of fresh concrete, and excessive impurities that may weaken the mechanical properties of concrete (K. P. Verian et al., 2018). The water absorption varies from (10.1 to 18.9) % in coarse recycled brick aggregate, up to twenty-five times higher than natural aggregate. And the dry density of coarse recycled brick aggregate, which ranges from ; S Kenai, 2008 and Debieb . F ( er than that of natural gravel , is typically low 3 to 2700 kg/m 1800 M T Uddin et al.,2017). Whereas when using fine recycled brick aggregate, density and water absorption are two major differences between sand and fine RBA. Fine RBA mainly derived from crushed bricks had a density of between 2000 and 2500 kg/m3, which was lower than natural sand. The water absorption of fine RBA was found to be between (12 to 15)%, which is more than 10 times higher than natural sand ( .,2014). the compressive strength Between the ages of 28 and 90 days, for fine RBA-containing mixture increased, and the increase was greater than that of conventional concrete and fine RCA-containing concrete. the explanation could be the, presence of silica and alumina in crushed bricks, which could cause pozzolanic reactions( J M Khatib, 2005). Another reason could be a lower w/c ratio in concrete mixtures with fine RA, which is caused by non-compensation of RA's high water absorption, resulting in a lower effective w/c ratio. Other studies that measured the w/c ratio based on RA's water absorption corroborated this hypothesis. These studies found no significant differences in the rate of strength growth between the ages of 28 and 90 days (Debieb & Kenai, 2008; Alves et al.,2014).
. Application of RBA instead of natural aggregate in mortar and concrete is the modern trend and many investigation have been done to estimate the characteristic of performance for the recycled concrete aggregate and mortar, the literature reviews of some studies are summarizing in Table 3

CONCLUSIONS
 the potential of using (WB) as partial replacement of cement or aggregate (course or fine) to produce sustainable concrete summarized in This review  The clear benefit of using the waste brick in concrete is the saving of natural resources , energy savings and reduce carbon dioxide CO2 emissions that are depleted during the cement and concrete production process.  Permit the use of waste brick powder as a partial substitute of cement with replacement level up to 10% for the manufacture of concrete because of the pozzolanic activity for it.  The utilize of brick powder helps to raises the density of concrete resulting lower pores and more compacted concrete  The using of waste brick powder can minimizing the corrosion of steel reinforcement .  The use of fine brick aggregate con improve strength and reduce the chlorides penetration in to concrete, if used by no more than 10%