Kiln Dust Research Articles

THE EFFECT OF CEMENT KILN DUST ON THE PROPERTIES OF CEMENT

Due to the nature of the technological process, the cement industry is a significant source of dust. Managing industrial waste is a global problem worldwide; cement kiln dust is an example of such waste. The dust from the cement kiln is a by-product of the cement production process obtained during the grinding and burning of the raw materials inside the cement kiln. Still, due to its high alkaline content, it cannot be returned to the kiln, but its disposal and landfill can cause many environmental problems. It is necessary to find alternative methods for its utilization. Due to its fineness and composition like that of cement, there is a growing interest in the use of this powder as a partial substitute for ordinary Portland cement. The purpose of this paper is to investigate the influence of dust obtained during the production of cement clinker on the properties of cement (specific surface area, standard consistency, setting time, and compressive strength) and its implications in the conditions of its application.

Geomechanical aspects of stabilizing arsenic trioxide roaster waste in cemented paste backfill at the Giant Mine, Canada

Giant Mine, an abandoned gold mine near Yellowknife in the Northwest Territories of Canada, generated significant arsenic trioxide roaster waste (ATRW) during its operations, posing a substantial environmental hazard. This study explored the feasibility of stabilizing ATRW by incorporating it into cemented paste backfill (CPB). Using response surface methodology (RSM), CPB samples with varying mixing ratios were analyzed to identify key parameters influencing strength. Unconfined compressive strength (UCS) tests assessed physical stability, while saturated hydraulic conductivity and computed tomography (CT) analyses examined the microstructure of the CPB. The results revealed that CPB samples prepared with general use (GU) cement exhibited significantly higher strength than those with a GU and lime kiln dust (LKD) mixture. Binder and solid contents were identified as the most critical factors influencing UCS, with binder content having a more pronounced influence. Curing time was found to be non-significant. Higher binder and solid contents correlated with higher UCS values in the CPB samples. The addition of 10% wt. ATRW reduced the UCS by over 30%, particularly in samples with lower binder and solid contents. Although microstructure differences were not evident in saturated hydraulic conductivity tests, CT scans showed increased formation of high-density arsenic-containing materials in samples with the highest UCS, especially those using GU binder. These findings suggest that optimizing binder and solid contents is crucial for enhancing CPB strength and effectively stabilizing ATRW.

The influence of volcanic ash (VA) on the mechanical properties and freeze-thaw durability of lime kiln dust (LKD)-stabilized kaolin clayey soil

Improving soft clay soil's mechanical properties and durability has been the subject of intense research. In this context, traditional stabilizers such as cement and lime have been introduced as the most widely used materials. However, the utilization of these conventional additives poses several challenges due to recent global concerns regarding the reduction of greenhouse gas emissions. Therefore, international research is shifting toward using environmentally friendly soil-stabilizing waste materials. This study, for the first time, evaluates the stabilization of kaolin clay soil using lime kiln dust (LKD) as a high CaO content waste pozzolan and volcanic ash (VA) as a natural pozzolan with considerable SiO2 and Al2O3 contents. In general, the research aims to demonstrate the effective performance of these two inexpensive and environmentally friendly additives in improving the mechanical characteristics and durability of kaolin clay soil, thereby providing the essential groundwork for the practical application of this method in stabilizing soft clay soil. This study included preparing samples with LKD at 3%, 5%, 7%, and 10% of the dry weight of clay and replacing LKD with VA at 0%, 25%, 75%, and 100%. The specimens were cured for 3, 7, and 28 days. Following the curing process, the optimal sample was subjected to varying numbers of freeze-thaw (F-T) cycles. The samples were examined by conducting a series of standard compaction, unconfined compressive strength (UCS), ultrasonic pulse velocity (UPV), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) tests at different stages of adding stabilizers, as well as before and after exposure of F-T cycles. The findings revealed that adding LKD and VA increased the UCS by accelerating and improving the pozzolanic and hydration reactions. Also, the combination of LKD and VA in kaolin soil enhanced F-T durability, resulting in less strength deterioration even after 10 cycles, when compared to the untreated control sample. In particular, the optimal mixture containing 5% LKD and 25% VA replacement improved 11 times in UCS compared to untreated kaolin clay and showed a slight reduction of only 7% after 10 F-T cycles. Overall, the incorporation of LKD and VA enhanced the mechanical properties and F-T durability of kaolin clay soil, making it a low-cost, sustainable, and eco-friendly option for soil improvement.

Ultrasonic Non-Destructive Testing of Accelerated Carbonation Cured-Eco-Bricks

This study aimed to investigate the behavior of accelerated carbonation-cured laboratory specimens using the ultrasonic non-destructive testing (UNDT) method and compare the results with the destructive testing (DT) method. The materials used in the study included a blend of lime kiln dust and ground granulated blast furnace slag (LKD-GBFS) wastes, natural fine aggregate (sand), and alternative fine aggregates from waste tires. The chemical analysis of the LKD and GBFS samples highlighted them as suitable alternatives to OPC, hence their utilization in the study. A 60:40 (LKD-GBFS) blending ratio and a 1:2 mix design (one part LKD-GBFS blend and two part sand) was considered. The natural fine aggregate was partially replaced with fine waste tire rubber crumbs (TRCs) in stepped increments of 0, 5, and 10% by the volume of the sand. The samples produced were cured using three curing regimens: humid curing (HC), accelerated carbonation curing (ACC) with no water curing (NWC) afterwards, and water curing after carbonation (WC). From the results, an exponential model was developed, which showed a direct correlation between the UNDT and DT results. The developed model is a useful tool that can predict the CS of carbonated samples when cast samples are unavailable. Lastly, a total CO2 uptake of 15,912 g (15.9 kg) was recorded, which underscores ACC as a promising curing technique that can be utilized in the construction industry. This technique will bring about savings in terms of the time required to produce masonry units while promoting a change in the basic assumptions of a safer and cleaner environment.

Freeze-thaw durability of clayey soils stabilized by alkaline-activated kaolin and recycled cement kiln dust

Weak soils pose significant challenges for civil engineering projects, particularly in cold regions. Stabilizing such soils with additives is a common practice to enhance their geotechnical properties. This research aimed to evaluate the durability of clayey soils stabilized by alkaline-activated kaolin at 10, 25, and 50%, along with 10% recycled cement kiln dust (CKD). The stabilization process involved curing the soils at different temperatures (40, 60, and 80°C) for varying durations (1, 7, 14, and 28 days). The stabilized soils underwent 5, 10, and 20 freeze-thaw (F-T) cycles to evaluate their durability. The results indicated F-T cycling led to a reduction in the unconfined compressive strength (UCS) of unstabilized soils, with a more pronounced impact as the number of cycles increased. However, this adverse effect was mitigated by additive stabilization. The improvement in UCS in stabilized soils was directly linked to the additive content, curing duration, and temperature. Both additives demonstrated superior resistance to F-T cycles, with CKD outperforming kaolin. These findings provide guidelines for utilizing kaolin and CKD for earthwork applications in cold regions with economic and sustainability advantages.

Sustainable soil stabilization using industrial waste ash: Enhancing expansive clay properties

This study investigates the use of various industrial waste materials—silica fume (SF), cement kiln dust (CKD), calcium carbide residue (CCR), rice husk ash (RHA), and ground granulated blast furnace slag (GGBS)—as eco-friendly stabilizers for expansive clay soil (ECS). Laboratory tests were conducted to assess the impact of different proportions (3 %, 6 %, and 9 %) of these additives on the soil's physical, mechanical, and microstructural properties. Results indicated that the inclusion of industrial waste significantly improved the soil's behavior, with notable reductions in liquid limit (up to 37.66 %), plasticity index (up to 74.76 %), and swell potential. Additionally, unconfined compressive strength (UCS) and shear strength increased substantially, with UCS values rising from 114.64 kPa to 1582.91 kPa at 30 days of curing for 9 % GGBS. Microstructural analyses confirmed the formation of cementitious compounds, which enhanced soil particle bonding and durability. These findings suggest that industrial waste materials can serve as effective and sustainable alternatives to traditional soil stabilizers, offering both performance improvements and environmental benefits.

Hydration and Mechanical Properties of Cement Kiln Dust-Blended Cement Composite

This study aims to investigate the effects of cement kiln dust (CKD) on the hydration reactions and mechanical properties of cement, and to evaluate its potential for use as a supplementary cementitious material (SCM). The key variables are the CKD type and the replacement ratio. Cement paste and mortar specimens containing CKD were prepared to examine their effects on the cement hydration and mechanical properties. The effect on hydration was assessed using setting time measurements, heat of hydration tests, and thermogravimetric analyses (TG). In addition, compressive strength tests were conducted to evaluate the effect of CKD on the mechanical properties of the cement. The results indicated that CKD promoted early-age cement hydration and enhanced the early-age mechanical properties. However, owing to its lack of pozzolanic reactivity, it did not significantly affect long-term hydration. Given that the effects of CKD vary slightly depending on its chemical composition, careful consideration of CKD’s properties suggests that its potential use as an SCM is promising.

Effectiveness of adding kaolin to Cement and Cement kiln Dust Mortar

Abstract The objective of this investigation is to discover a binder material derived from cement kiln bypass dust mixed with kaolin without calcination at ambient temperature. A total of nine groups were fabricated with eighty-one cubes containing different mixtures. These mixtures were primarily based on a cement mortar contained a 50% combination of cement and cement kiln dust, along with varying amounts of kaolin (10%, 15%, and 20% by weight). The impact of these different ratios on the mechanical properties of mortar, as well as the hydration products, was studied using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The findings indicated a positive enhancement in the mortar compressive strength at 10% kaolin, ranging from 70% to 144% after 7 and 28 days of curing, in comparison with the compressive strength of mortar without kaolin.

Integrated CO2 Capture and Mineralization Based on Monoethanolamine and Lime Kiln Dust

Integrated CO₂ Capture and Mineralization Based on Monoethanolamine and Lime Kiln Dust

Enhancement of Strength and Compressibility of Black Cotton Soil Using Ground Granulated Blast-Furnace Slag (GGBS)–Cement Kiln Dust Columns

Enhancement of Strength and Compressibility of Black Cotton Soil Using Ground Granulated Blast-Furnace Slag (GGBS)–Cement Kiln Dust Columns

Assessment of Human Health Risk Caused by Heavy Metals in Kiln Dust from Coal-Fired Clay Brick Factories in Türkiye

AbstractHeavy metal (HM) pollution from natural processes and different anthropogenic activities pose significant human and environmental health risks because of their stability, non-degradable properties, and high toxicity. HM released into the air in the form of dust can enter the human body via ingestion, inhalation, and dermal contact. Keeping in mind the significance of estimating the risk from HM in different environments, the carcinogenic and non-carcinogenic health risks to workers caused by HM in kiln dust (KD) samples collected from coal-fired clay brick factories in the Western Black Sea Region of Türkiye were assessed for the first time in this study. The concentrations of major and minor oxides and HMs in the collected KD samples were analyzed using energy-dispersive X-ray fluorescence spectrometry. The average concentrations of Fe, Mn, Cr, Ni, V, Zn, Cu, As, Co and Pb analyzed in thirty-three KD samples were determined as 65444, 768, 251, 249, 248, 122, 60, 52, 42 and 16 mg/kg dw, respectively. The average levels of Ni, As, Cr, Co and Cu exceed the maximum contaminant levels recommended in the Turkish Regulation on Control of Soil Pollution. Carcinogenic and non-carcinogenic human health risk assessments for workers via three exposure pathways were carried out, estimating the hazard index (HI) and total carcinogenic risk (TCR) index, respectively. The HI values (< 1) revealed no possible non-carcinogenic health risk due to exposure to all HMs in the studied KD samples. The average TCR value revealed that the potential cancer risks for Ni, As, Cr, and Pb were slightly above the safe limit and required monitoring and further investigation for these HMs.

Investigating the Impact of Ground Granulated Blast Furnace Slag (GGBS) and Cement Kiln Dust (CKD) on fine grained Soil Subgrade in Al Hillah City

Abstract In many parts of the world, fine grained soils are regarded as one of the major concerns for civil engineering projects. To mitigate these problems, fine grained soils are typically replaced with stronger materials. However, due to the high cost of this approach, various researchers have tried alternative approaches, the most popular of which is soil stabilization. This method could be deemed suitable for pavements. The research focuses on stabilizing fine soil through the utilization of cement kiln dust (CKD) and ground granulated blast slag (GGBS). This research involves treating fine soil with 10% of the total binder consist from (GGBS+CKD), with the amount of GGBS to CKD determined by dry soil weight as follows: (10% GGBS + 0% CKD), (8% GGBS + 2% CKD), (6% GGBS + 4% CKD), (2% GGBS + 8% CKD), and (0% GGBS + 10% CKD). The compaction parameters, consistency limitations, and the findings of the Unconfined Compressive Strength (UCS) test were used to assess the enhancement levels. In addition, specimens were subjected to UCS testing after (7-28) days of curing. The findings demonstrated that the combination of GGBS activated by CKD notably enhanced the physical characteristics of fine soil. The Plasticity Index (PI) decreased from 7.4 for untreated soil to 4.8 for a mixture containing 10% binder, comprised of 2% GGBS and 8% CKD, and to 4.25 for a single-binder mixture with 10% CKD. Furthermore, the unconfined compressive strength test (UCS) results indicated that a 10% binder mixture of 8% GGBS and 2% CKD increased the UCS by 2.9 to 5.9 times compared to untreated soil after 7-28 days of curing.

Experimental Investigation of Recycling Cement Kiln Dust (CKD) as a Co-Binder Material in Cemented Paste Backfill (CPB) Made with Copper Tailings

Experimental Investigation of Recycling Cement Kiln Dust (CKD) as a Co-Binder Material in Cemented Paste Backfill (CPB) Made with Copper Tailings

Mechanical performance of eco-friendly self-compacting concrete (SCC) mixtures and two-way slabs partially containing cement kiln dust as cement replacement and internally reinforced with waste plastic mesh

A large quantity of cement kiln dust (CKD) is produced annually during the production of Portland cement. The majority of the produced CKD remains unused except in specific cases related to soil stabilization projects. The current research investigates the production of self-compacting concrete (SCC) mixtures, in which CKD is used as a substitute for cement in different weight proportions, 3 %, 6 %, 9 %, 12 %, and 15 %. The hardened mechanical properties of SCC, such as compressive strength, splitting tensile strength, and flexural strength, as well as the fresh state characteristics (i.e., slump flow diameter, T500, V-funnel, and L-box tests), were recorded and compared with the control mixture which was entirely cast using cement. Results revealed that with an increase in the CKD content beyond 6 %, the slump flow diameter of SCC mixtures significantly decreased. Also, the increase ratios in the V-Funnel flow time for self-compacting concrete mixtures, when replacing cement with CKD ratios of 3 %, 6 %, 9 %, 12 %, and 15 %, were 13.3 %, 30 %, 46 %, 58 %, and 66.7 % respectively, compared with the reference mixture. Additionally, the impact behavior of two-way SCC slabs cast using CKD ratios ranging from 3 to 15 % and internally strengthened using various patterns of recycled plastic mesh was investigated. Strengthening the SCC slabs using two layers of recycled plastic grids proved to be effective in preventing the projectile from penetrating the whole thickness of the SCC slabs, regardless of the CKD content.

Utilization of accelerated weathering of limestone captured carbon dioxide (CO2) with cement kiln dust to produce building material

The accelerated weathering of limestone (AWL) process is an inexpensive and eco-friendly carbon dioxide (CO2) capture process with comparable performance to amine-based systems. However, the generated calcium bicarbonate (Ca(HCO3)2) solution lacks an effective utilization alternative. Aside from that, the current solid waste utilization alternatives (i.e., carbon mineralization and partial replacement of conventional binders) lack the capability to effectively curb the tremendous production rate of solid waste (i.e., cement kiln dust (CKD)). To address both gaps, this study developed a novel Ca(HCO3)2 solution utilization alternative with CKD as the sole binder to produce a building material termed CKD-bicarbonate lime mortar (BLM). This work aims to identify the optimal mix ratio for CKD-BLM to achieve maximum compressive strength via a series of studies; (i) liquid medium, (ii) Ca(HCO3)2 solution volume, and (iii) sand:CKD mix ratio. From the findings, it was found that CKD-BLM at the optimal CKD:sand:Ca(HCO3)2 mix ratio of 1:0.45:0.29 exhibits the highest compressive strength of 2.09 MPa, surpassing the compressive strength standard of 1.70 MPa set by the ASTM C141 while having acceptable workability of 118 % which is within the standard workability range of 105–155 % set by ASTM C270. However, the CKD-BLM sample exhibits high leaching of Ca, Si, Na and Cl which does not meet the environmental regulation. This was resolved by applying a waterproof coating that effectively curbed the leaching by 28.84–99 %. Overall, this study successfully developed a building material with industrial wastes (i.e., Ca(HCO3)2 solution and CKD) that surpasses the performance of conventional lime mortar while utilizing up to 0.22 kg CO2.kg CKD-BLM_1:0.45:0.29−1.

The effective treatment of dye-containing simulated wastewater by using the cement kiln dust as an industrial waste adsorbent

This study compares the adsorption behavior of both Methylene Blue (MB) and Congo Red (CR) dyes on the surfaces of cement kiln dust (CKD) powder from the experimentally simulated wastewater solution. The cement kiln dust powder was characterized using X-ray Fluorescence (XRF), X-ray diffraction (XRD), N2 adsorption–desorption Brunauer–Emmett–Teller (BET), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) tests. The adsorption for such dyes was studied under varying mixing contact times, temperatures, and pH as well as various initial concentrations of both dyes and adsorbent using the batch mode experiments. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were applied, and the results revealed that the pseudo-second-order fitted well to the kinetic data. Thermodynamic parameters stated that the adsorption process was endothermic. Studying Linear and nonlinear forms of Langmuir and Freundlich's adsorption isotherms revealed that the adsorption process was followed by both homogeneous mono-layer and heterogeneous multilayer coverage on the active sites of cement kiln dust particles. The data showed that the adsorption capacities of the methylene blue and Congo red dyes were 58.43 and 123.42 mg/g, respectively and cement kiln dust is an adsorbent with little cost for the treatment of wastewater.

A comparative study of the mechanical and thermal properties of EPDM rubber/cement kiln dust composite cured by ionizing radiation

In this work, cement kiln dust (CKD) will be studied as an unconventional filler for ethylene-propylene-diene terpolymer (EPDM) rubber as an alternative to silica, which is widely used as filler for many types of rubber. (EPDM)/CKD rubber composites were fabricated using ionizing radiation. EPDM rubber was blended with different portions of cement-kiln dust 5, 10, 15, 20, 25, and 30 phr (phr = parts per hundred rubber). The prepared composites were cured by exposing to different doses of gamma rays up to 150 kGy to enhance the crosslinking of the EPDM rubber. The thermo-mechanical properties of the EPDM/CKD and EPDM/Si composites were investigated as a function of irradiation dose. The results showed a significant improvement in elongation and tensile strength by incorporating cement dust into EPDM rubber up to 20 phr, which is not significantly different from composites incorporated with silica. Gamma irradiation significantly improved the properties of all formulations.

Formulation of high-recycled-content hydraulic cements based on alkali aluminosilicate chemistry and mechanochemical processing techniques

The current study investigates the potential of various waste materials and industrial by-products for formulating high-recycled content hydraulic cement, leveraging alkali aluminosilicate chemistry principles. Through rigorous characterization employing X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, thermogravimetric analysis (TGA), and Scanning Electron Microscopy (SEM), alongside alkalinity and alkali solubility assessments, the chemical and mineralogical compositions of waste brick, lime kiln dust, cement kiln dust, waste glass, gypsum, foundry sand, granulated blast furnace slag, and impounded coal ash were unveiled. Silicon and aluminum were found abundantly in these materials, with lime kiln dust and slag contributing calcium. A thoroughly crafted blend, enriched with alkalis, underwent mechanochemical activation to yield a hydraulic cement finely tuned to meet specific chemical ratios required for effective alkali aluminosilicate reactions. Upon hydration, this innovative cement exhibited rapid early strength development, achieving a commendable compressive strength of 32 MPa within 28 days a performance on par with standard Portland cement. Remarkably, the heat of hydration profiles revealed a prompt onset of hydration reactions, marked by a significant exothermic peak within the initial hours, in contrast to the gradual peak observed with Portland cement. TGA/DTA results further corroborated the thermal stability of the hydration products formed. Alkali-solubility assessments of the raw materials emerged as reliable indicators of their reactivity within the cement matrix, with solubility values exceeding 20 % for waste glass and impounded coal ash, signifying their high potential for alkali activation. The culmination of this research underscores the feasibility of re-composing waste materials to craft alkali aluminosilicate cement, offering performance akin to conventional options. These findings advocate for the adoption of sustainable material utilization in construction, paving the way for enhanced industrial symbiosis in cement production.

Characterization and utilization capabilities of industrial wastes for green bricks production

BackgroundThe goal of this study is to develop a feasible and sustainable solution to manage the use of industrial wastes of ground granulated blast-furnace steel slag (GGBS) activated by cement kiln dust (CKD) and quicklime (QL). Using activated GGBS in the manufacture of stabilized green bricks is still uncommon in Egypt in such applications. Five clay-based mixtures, each with varying replacement ratios (5–10, wt.%) of CKD and QL, were studied. Laboratory tests were conducted on cylindrical specimens made from these mixtures, which were left to cure for periods of up to 60 days. The raw materials and lab-made specimens were analyzed using particle size analysis, differential thermal analysis, X-ray fluorescence, and X-ray diffraction techniques. The physical and mechanical properties of the cured specimens were also determined and evaluated according to standard specifications. Furthermore, the durability of the cured specimens was evaluated against collapsibility in water.ResuItsIt has been observed that adding QL and CKD to the stabilized green specimens of different mixes can enhance their engineering properties with curing age increasing. This is due to the pozzolanic reaction, which fills the pore structure with calcium silicate hydrates and calcium aluminate hydrates gel. The ratio of QL and CKD used significantly affected the engineering properties of the specimens. The study found that using 20% GGBS and 5% QL led to an increase in compressive strength (266 kg/cm2) at the density of (2.15 g/cm3), while also water absorption was reduced (8%) to give superior results. When GGBS and CKD were combined, a higher content of CKD (10 wt.%) gave better results compared to (5 wt.%) CKD. Furthermore, the physical and mechanical properties of the tested specimens (MD 1, MD II, MD III and MD IV) met the acceptable limits of dry compressive strength (30–70 kg/cm2), water absorption (8–15%), and density (1.7–2 gm/cm3), as specified by the Egyptian standard specifications for buildings used compressed earth blocks.ConclusionThe CKD and QL act as alkali activators for GGBS and can be utilized in masonry construction.

Durability Assessment of Eco-Friendly Bricks Containing Lime Kiln Dust and Tire Rubber Waste Using Mercury Intrusion Porosimetry

The global challenge faced due to the impact of the construction industry on climate change, along with the issues surrounding sustainable waste disposal, has necessitated various research on using waste products as eco-friendly alternatives in construction. In this study, the avoidance of waste disposal through landfills in Australia was encouraged by incorporating lime kiln dust (LKD) and tire rubber waste (TRW) into masonry mixes to manufacture green bricks. Furthermore, the investigations in this article highlight the use of mercury intrusion porosimetry (MIP) to determine the durability of the LKD-TRW bricks when exposed to freeze–thaw (F-T) cycles by examining the pore size distribution within the bricks. The LKD waste was blended with ground granulated blast furnace slag (GGBFS) at a 70:30 blending ratio and combined with the TRW in stepped increments of 5% from 0 to 20% to produce these eco-friendly bricks. The compressive strength (CS), flexural strength (FS), frost resistance (FR), pore size distribution according to mercury intrusion porosimetry (MIP), and the water absorption (WA) properties of the bricks were assessed. The CS and FS values at 28 days of curing were recorded as 6.17, 5.25, and 3.09 MPa and 2.52, 2, and 1.55 MPa for 0, 5, and 10% TRW contents, respectively. Durability assessments using the F-T test showed that the bricks produced with 0% TRW passed as frost-resistant bricks. Furthermore, the results from the MIP test showed a total pore volume of 0.033 mL/g at 3 µm pore size for the 0% TRW content, further confirming its durability. Hence, the 0% LKD-TRW bricks can be utilized in cold regions where temperatures can be as low as −43 °C without deteriorating. Lastly, WA values of 7.25, 11.76, and 14.96% were recorded for the bricks with 0, 5, and 10% TRW, respectively, after the 28-day curing period. From all of the results obtained from the laboratory investigations, the LKD-TRW bricks produced with up to 10% TRW were within the satisfactory engineering requirements for masonry units.