Red Clay Brick Waste Research Articles

Early-age structural build-up and rheological assessment of alkali-activated slag-red clay brick waste pastes: Influence of silica modulus and precursors proportions

Sustainability plays a crucial role in the current context of the cement industry, and alkali-activated materials (AAMs) are emerging as eco-efficient alternative binders. On the other hand, the massive generation of red brick waste worldwide and its lack of a defined destination emphasizes this material as an alternative precursor that has been insufficiently explored in the literature. Based on this context, the present study aims to investigate the structural build-up, reaction kinetics, and rheological properties of alkali-activated pastes based on blast furnace slag (BFS) and red clay brick waste (RBCW). Fresh properties such as structural build-up, rheology, and reaction kinetics are lacking in the literature on RCBW-based AAMs, highlighting these properties as a research gap to be filled and discussed in depth in this paper. The flow sweep test was performed, linked to yield stress and viscosity properties. The structural build-up was evaluated by strain sweep and small amplitude oscillatory shear (SAOS) tests based on viscoelastic parameters: storage modulus, loss modulus, and phase angle. Isothermal calorimetry and in-situ FTIR were also conducted to complement the analysis and provide insight into the reaction kinetics, chemical structure, and product formation. Higher silica modulus (Ms) resulted in a lower structural build-up rate and a delayed reaction. Higher content of RCBW resulted in a delayed structuration process, which was linked to a delay in the precipitation of aluminosilicate gels. Early increase in the structural build-up in 25 % and 50 % RCBW blends (Ms = 1.0) is associated with the early formation of a well-percolated network.

Upcycling Fly Ash, Red Clay Brick Waste, and Paper Sludge as Feedstock for Manufacturing a Lightweight Extruded Composite: Design and Characterization

In the context of the circular economy and the adoption of one of its business models, namely ”resource recovery”, this study presents an opportunity to valorize industrial and urban wastes using alkaline activation technology to produce hybrid binders. Several alkali-activated binders were produced using response surface methodology based on a mixture of 45/45/10 clay brick waste, fly ash, and Portland cement. The compressive strength and setting time of each were evaluated. The hybrid cementitious pastes achieved up to 45 MPa after 28 days of setting. Based on the experimental data, two binders were selected as the cementitious matrix for composites, with paper sludge as the lightweight aggregate. Incorporating up to 45% volume of paper sludge allowed extrusion of the materials. The addition of paper sludge reduced the compressive and flexural strength. These results were explained by the decrease in density and the increase in porosity. However, there was an improvement in the thermal properties of the composites; in particular, the thermal conductivity range between 0.35 and 0.49 W/mK. Finally, it was found that the composites with 25% volume of paper sludge had the best combination of properties, positioning them as potential construction materials.

3D Printing of Hybrid Cements Based on High Contents of Powders from Concrete, Ceramic and Brick Waste Chemically Activated with Sodium Sulphate (Na2SO4)

This article evaluates the synthesis, characterization and 3D printing of hybrid cements based on high (70%) contents of powders from concrete waste (CoW), ceramic waste (CeW) and red clay brick waste (RCBW) from construction and demolition waste. For the synthesis of the hybrid cements, 30% (by weight) of ordinary Portland cement (OPC) was added. Sodium sulphate (Na2SO4) (4%) was used as a chemical activator. The effect of the liquid/solid ratio on the properties in the fresh state of the mixes was studied by means of minislump, flowability index, and buildability tests. The compressive strength was evaluated at 3, 7, 28 and 90 days of curing at room temperature (≈25 °C), obtaining strengths of up to 30.7 MPa (CoW), 37.0 MPa (CeW) and 33.2 MPa (RCBW) with an L/S ratio of 0.30. The results obtained allowed selecting the CoW 0.30, CeW 0.33 and RCBW 0.38 mixes as optimal for carrying out 3D printing tests on a laboratory scale, successfully printing elements with good print quality, adequate buildability, and compressive strength (CoW 0.30 = 18.2 MPa, CeW 0.33 = 27.7 MPa and RCBW 0.38 = 21.7 MPa) higher than the structural limit (≥17.5 MPa) established for concrete by Colombian Regulations for Earthquake Resistant Construction (NSR-10).

Influence of Sugar Cane Straw Ash in Mechanical and Microstructural Characteristics of Alkali-Activated Materials Based on Red Clay Brick Waste

Influence of Sugar Cane Straw Ash in Mechanical and Microstructural Characteristics of Alkali-Activated Materials Based on Red Clay Brick Waste

Utilization of red clay brick waste in the green preparation of an efficient porous nanocomposite for phenol adsorption: Characterization, experiments and statistical physics treatment

Red clay brick waste was utilized, for the first time, in the green preparation of nanoscale zero-valent iron (nZVI) to impregnate with activated charcoal (ACh). The as-synthesized nZVI@ACh composite was characterized via X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry, thermogravimetric analysis (TG) and its derivative thermogravimetry (DTG), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). This novel material was employed for phenol remediation at 25, 35, and 45 °C and pH 7. The results indicated that the prepared ZVI nanoparticles could be either trapped or distributed on the ACh structure. Experimental studies and their modeling with statistical physics theory were applied to analyze the phenol adsorption performance and mechanism using the nZVI@ACh. The phenol adsorption data fitted well to the Langmuir model, with maximum adsorption capacities of 122.85, 137.46, and 152.22 mg/g at 25°, 35°, and 45 °C, respectively. Theoretical calculations via statistical physics indicated that phenol molecules were removed on the nZVI@ACh following the hypothesis of the advanced monolayer model. The number of molecules adsorbed per site (n) ranged from 1.13 to 1.26 suggesting the involvement of vertical geometry and multi-molecular mechanism at all temperatures. The increment of the receptor sites density (NM) from 83.47 to 121.40 mg/g and the adsorption capacity at saturation (Qsat) from 104.75 to 137.19 mg/g with increasing temperature suggested the endothermic behavior of this removal process. Energetically, the phenol adsorption was directed by physical forces with adsorption energies (ΔE) ranging from 13.85 to 16.45 kJ/mol. Macroscopically, phenol adsorption onto nZVI@ACh was spontaneous according to the calculated thermodynamic functions. The developed nZVI@ACh adsorbent can be easily regenerated and reused preserving its competitive adsorption performance. Overall, these results offer a new approach that takes the Fe-rich solid wastes to the next standard in the design of outstanding and low-cost adsorbents for wastewater remediation. Also, the experimental study supported by the theoretical analysis generated new insights of the adsorption system at the micro- and macroscopic scales.

The potential application of cement kiln dust-red clay brick waste-silica fume composites as unfired building bricks with outstanding properties and high ability to CO2-capture

In this paper, a simple eco-sustainable approach was applied to synthesize unfired building bricks, in which cement kiln dust (CKD), red clay brick waste (RCBW), and silica fume (SF) were the main ingredients. The CKD-RCBW-SF composite was adjusted at different weight ratios of 50-50-0, 50-40-10, 50-30-20, and 50-20-30 wt%. The fabrication process included three main stages, i.e. dry blending, water mixing, and casting. Different curing conditions were applied (water, air, and CO2-gas) to assess the effect of curing type on the performance of the prepared bricks. The results demonstrated that increasing SF content caused an increase in compressive strength escorted by a significant decrease in bulk density of the hardened bricks, regardless of curing type. All over of the curing media, the hardened samples cured in water showed the highest performance. The highest 28-days compressive strength value (47 MPa) was achieved by hardened CKD-RCBW-SF composite (at a weight ratio of 50-20-30 wt%, respectively) cured in water. Unlike its effect on the physical and mechanical performances, increasing SF content negatively influenced the capability of the hardened bricks to CO2-sequestration. Specifically, the hardened bricks with no SF cured in CO2 gas for 28-days can sequestrate higher CO2 content (~75 kg/ton) compared to the hardened samples containing 30 wt% SF (~59 kg/tonne). The proposed method is not only considered as an innovative approach for mitigating CO2 emission resulted from the traditional bricks industry, but also strongly contributed to waste disposal, the conservation of the reserve of natural materials, the decrease of energy demand and processing cost, and the enhancement of the ability of the hardened bricks to CO2-capture.

Eco-House Prototype Constructed with Alkali-Activated Blocks: Material Production, Characterization, Design, Construction, and Environmental Impact.

The interest of the construction industry in alkali-activated materials has increased to the extent that these materials are recognized as alternatives to ordinary Portland cement-based materials in the quest for sustainable construction. This article presents the design and construction of a prototype of an eco-friendly house built from concrete blocks produced using alkali activation technology or geopolymerization. The prototype meets the requirements of the current Colombian Regulations for Earthquake Resistant Buildings (NSR-10) and includes standards related to the performance of the materials, design, and construction method for earthquake-resistant confined masonry of one- or two-story buildings. The alkali-activated blocks were obtained from different precursors (aluminosilicates), including a natural volcanic pozzolan, ground granulated blast furnace slag, fly ash, construction and demolition waste (concrete, ceramic, brick, and mortar), and red clay brick waste. The physical-mechanical characterization of the alkali-activated blocks allowed their classification according to the structural specifications of the Colombian Technical Standard NTC 4026 (equivalent to ASTM C90). The global warming potential (GWP) or “carbon footprint” attributed to the raw materials of alkali-activated blocks was lower (25.4–54.7%) than that of the reference blocks (ordinary Portland cement concrete blocks). These results demonstrate the potential of alkali-activated materials for application in the construction of eco-friendly houses.

Synthesis and optimization of binary systems of brick and concrete wastes geopolymers at ambient environment

This study investigates the use of binary system of concrete waste (CW) and red clay brick waste (BW) to develop geopolymer binders with appropriate fresh properties and high mechanical strengths at ambient curing. Binary waste geopolymers were adjusted based on the contents of BW and CW precursors between 20% and 80% and predetermined liquid/solid (L/S) and oxide ratios of SiO2/Al2O3 and Na2O/SiO2. The effect of oxide ratios on the fresh and mechanical properties were considered by assessing the flow spread diameter, initial and final setting time and compressive strengths of BW + CW binders. Further optimization of the optimal binary BW + CW mixture was also explored by partial replacement of BW + CW precursors with 15%, 30% and 45% wt.% of ground granulated blast furnace slag (GGBS), metakaolin (MK), class C fly ash (FA-C), class F fly ash (FA-F) at room temperature curing and by applying 24 h initial high temperatures of 50 °C, 75 °C, and 100 °C. Extensive microstructural study with X-ray diffraction and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and Fourier transformed infrared spectroscopy was performed to characterize the optimized compositions at various conditions. The results indicate that 40% CW + 60% BW, at SiO2/Al2O3 of 8.4 and Na2O/SiO2 of 0.18, was the optimal binary mix, which reached high mechanical properties at ambient curing. The addition of SCMs with elevated alumina or calcium contents permitted the geopolymer mixture to attain significant strength enhancements with very high mechanical strengths of more than 100 MPa at 28 days at room temperature. An advanced degree of geopolymerization and enhanced formation of intermixed C-A-S-H/C-S-H and N-A-S-H products was confirmed in relation to the well-adjusted SiO2/Al2O3 and Na2O/SiO2 ratios and optimized strength geopolymers.

Improving Alkali-Activated Binders Based on Red Clay Brick Waste with the Incorporation of Sugar Cane Straw Ash

Improving Alkali-Activated Binders Based on Red Clay Brick Waste with the Incorporation of Sugar Cane Straw Ash

Resistance of red clay brick waste/phosphorus slag-based geopolymer mortar to acid solutions of mild concentration

This work is devoted to the investigation of the resistance of geopolymer cement (GC) mortar based on mixture of red clay brick waste (RCBW) and phosphorus slag (PHS) in exposure to HCl and H2SO4 solutions of mild concentration. For this purpose, the GC mortar specimens were exposed to pH = 3 of each acid solution for 24 months. To prepare GC mortar, blend of RCBW and PHS was activated by water glass and NaOH and then hydrothermally cured. For comparison purpose, reference specimens were also prepared using high alumina and Portland cements. The durability of mortar specimens was evaluated by measuring the changes in compressive strength and mass as key parameters at predetermined time intervals. The structural and compositional changes of the reaction products were studied using appropriate characterization techniques. The obtained results disclosed that GC mortar exhibited an excellent acid resistance compared to reference mortars exhibiting significantly lower durability properties. The exposure to H2SO4 caused more deterioration in all specimens than the exposure to HCl owning to the adverse effect of gypsum formation, which results in the expansion and cracking of the paste matrix.

Strength Development and Pore Structure Characterisation of Binary Alkali-activated Binder Based on Tungsten Mining Waste

The mineralogical properties of tungsten mining waste mud (TMWM) make its valorisation and re-usage as an alumino-silicate source material to produce an alkali-activated binder without calcination is a challenge. Moreover, the dissolution of silicate and alumina species from TMWM is very slow. Despite the crystallinity of TMWM, this study demonstrates that its combination with other sources of the alumino-silicate source was the materials–such as red clay brick waste(RCBW),ground granulated blast furnace slag (GGBFS) and electric arc furnace slag (EAFS) – improved the compressive strength and the pore structure of the alkali-activated matrix.Thecombinedprecursors (90 vt.%TMWM+10 vt.%RCBW, 90 vt.%TMWM+10 vt.%GGBFS, and 90 vt.%TMWM+10 vt.%EAFS) were activated using a combination of alkaline activator solutions (sodium silicate and sodium hydroxide) with the ratio of 1:3(66.6wt.%sodiumsilicatecombined with 33.33 wt.% of NaOH 10M). The results show that the compressive strength increased from11.23MPa at 28 days to reach 24.98MPawhentheTMWMwaspartially replacedby10vt.%RCBW. In addition,this study shows that the interconnected porosity decreased where the critical pore size was reduced from 21.28 µm to 0.55 µm for the tungsten mining waste-based alkali-activated binder and the binary alkali-activated binder based on TMWM and RCBW.
 Keywords: Mining Waste, Alkali-activated, Microstructure, MIP, Metakaolin

Ultra-lightweight porous materials fabrication and hazardous lead-stabilization through alkali-activation/sintering of different industrial solid wastes

Abstract The beneficial use of alkali-activation/sintering process in the fabrication of open-celled cellular materials and lead solidification/stabilization (S/S) is the biggest challenge of the present work. Waste glass (WG), red-clay brick waste (RCBW), and lead-bearing-sludge (LBS) were used as silicate-rich-wastes in the foaming process. Porous materials with porosity ranging from 50 to 89% accompanied by low bulk density (0.73–0.27 g/cm3), low thermal conductivity (0.3–0.14 W/mK), and high compressive strength (3.4–14.2 MPa) were obtained when alkali activated WG, WG-RCBW, and WG-LBS fired at different elevated temperatures (700-900 °C). The results revealed that comparing with WG-foamed materials, the heating of WG activated by 4M-NaOH at 800 °C has resulted in the formation of foamed-glass with higher porosity, lower thermal conductivity, and lower bulk density. The use of RCBW, as a partial substituent of WG, represents the potential impact on the enhancement of foamed-material homogeneity. The dominant feature of the foamed-WG-LBS set is the formation of a porous structure with the biggest pore size and the lowest thermal conductivity. The leaching test proved that the applied alkali activation/sintering process has high efficacy on the Pb-stabilization.

Red clay brick and tungsten mining waste-based alkali-activated binder: Microstructural and mechanical properties

This paper illustrates the study on the synthesis of alkali-activated binders based on the combination of tungsten mining waste mud (TMWM) with red clay brick waste (RCBW) with the use of sodium hydroxide (SH) and sodium silicate (SS) solution as alkaline activators; with a solid/liquid weight ratio = 3, and the SS:SH weight ratio = 2:1. The synthesis of TMWM-RCBW alkali-activated binders was conducted at 60 ± 2 °C curing temperature for 24 h, by using different TMWM and RCBW volume proportions, namely (90:10, 80:20, 70:30, 60:40 and 50:50 vt.%). Mineralogical and microstructural characterisation was carried out by X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC), mercury intrusion porosimetry (MIP) and Fourier transform infrared spectroscopy (FT-IR). The FT-IR spectra and EDX analysis demonstrated that the higher dosage of RCBW content in the samples, the higher the formation of N–A–S–H and/or C–A–S–H and/or K–A–S–H and the combination (N,C)–A–S–H and/or (N,K) –A–S–H gels during the alkaline activation process. By SEM image analysis it was also verified that more gels are formed for more denser structure of the alkali-activated materials. The increase in the dosages of RCBW in the mixtures was also followed by an increase in compressive strength for all the tested ages. It developed from 25 to 59 MPa for samples with RCBW volume content dosage of 10% and 50% respectively. Also, the binder matrix becomes denser and compact by gradually increasing the RCBW dosage.

Eco-efficient alkali-activated cement based on red clay brick wastes suitable for the manufacturing of building materials

The objective of this study was to obtain hybrid-type binders at room temperature (25 °C) from the alkaline activation of a red clay brick waste and the addition of a reduced amount (≤30%) of Portland cement. Different types of activators were used, including solids (Na2SO4, Na2CO3, NaOH) and liquids (Na2SiO3xH2O). The results highlight the possibility of obtaining an eco-efficient, hybrid cement with compressive strengths of up to 102 MPa at 28 days and reductions of up to 73% in the global warming potential (expressed in kg·CO2·eq/MPa) associated with a Portland cement paste. Based on the optimum hybrid cement, a mortar was developed and used as a base material for the production of block and paver construction elements that comply with construction industry standards.

Alkali-activated building materials made with recycled construction and demolition wastes

The goal of this study was to test the viability of using red clay brick waste (RCBW), concrete waste (CW) and glass waste (GW) to produce alkali-activated cements (AACs) that can be used to fabricate blocks, pavers, roof tiles and tiles. The alkaline activators used were solutions of either NaOH or NaOH and waterglass. Ordinary Portland cement (OPC) was mixed with RCBW and CW in proportions of up to 30% to create hybrid cements. The AACs obtained with the RCBW, the CW and the GW exhibited maximum compressive strengths (28days) of 102, 33 and 57MPa, respectively.

Alternative cements based on alkali-activated red clay brick waste

The synthesis of alkali-activated and hybrid cements based on red clay brick waste was investigated using sodium hydroxide and sodium silicate solution as alkaline activators. The effect on the compressive strength of Na2O/SiO2 and SiO2/Al2O3 molar ratios and type of curing was evaluated. The combined presence of Portland cement (20%) and sodium silicate yielded a maximum compressive strength of 102.6MPa at 28 days and 25°C; this value is two times higher than the strength obtained in mixtures without Portland cement and 7.3 times higher than when sodium hydroxide is used. The results demonstrated the feasibility of using these materials to produce structural and non-structural construction elements.

Producción de elementos constructivos a partir de residuos de ladrillo activados alcalinamente

Se analiza la viabilidad de utilizar los residuos de ladrillo de arcilla roja (RL) para producir elementos constructivos, tipo bloque, adoquín y teja, mediante la técnica de activación alcalina. La producción de los elementos constructivos se basó en el desarrollo de un mortero híbrido de 48.61 MPa de resistencia a la compresión a los 28 días de curado a temperatura ambiente (25 °C). Para la síntesis del mortero híbrido se utilizó un porcentaje de adición de cemento portland (OPC) del 10 % en peso con respecto al RL. Como activadores alcalinos se usaron hidróxido de sodio (NaOH) grado industrial y silicato sódico comercial (Na2SiO3). Los elementos constructivos fueron caracterizados tanto física como mecánicamente de acuerdo con las normas técnicas colombianas (NTC). Se plantea este proceso como una alternativa de utilización de los RL y un aporte a la sostenibilidad ambiental.

Influence of calcium aluminate cement (CAC) on alkaline activation of red clay brick waste (RCBW)

In this paper, the effect of calcium aluminate cement (CAC) additions on the alkali activation of red clay brick waste (RCBW) was studied at room temperature and at 65 °C. RCBW was partially replaced with CAC (0–50 wt.%) and blends were activated with NaOH and sodium silicate solutions. The compressive strength evolution was tested on mortars and the nature of the reaction products was analysed by infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, microscopic studies and pH measurements. The results show that the use of CAC accelerates the activation process of RCBW so that 50 MPa were obtained in the blended mortars containing 40 wt.% CAC cured for 3 days at room temperature. CAC did not undergo normal hydration and only the C3AH6 phase was identified in the pastes blended with more than 30 wt.% CAC and cured at 65 °C, while the main reaction product was a cementitious gel containing Ca and Al from CAC.

Alkali-activated cements and mortars based on blast furnace slag and red clay brick waste

Abstract This study investigates the effects of adding various concentrations, sources and compositions of ground red clay brick waste (RCBW) on the properties of fresh and hardened pastes and mortars of alkali-activated slag. The method used to grind the granulated blast furnace slag (GBFS) and RCBW (separate and conjoint) is also assessed, along with the fineness (300–900 m2/kg) of the blended alkali-activated GBFS-RCBW cement, the alkali activator (sodium carbonate or sodium silicate) and the curing conditions (normal conditions or steam curing). The water requirement and setting time for the fresh pastes are also considered; and in the case of the hardened paste and mortar, the water absorption, density and compressive/flexural strength are measured after 1, 3, 7 and 28 days of aging. From the results obtained, it is demonstrated that the addition of 40% RCBW improves the 7- and 28-day strength of blended alkali-activated slag pastes and mortars, and can replace up to 60% of the slag without losing strength.

Properties and microstructure of alkali-activated red clay brick waste

Sintered red clay ceramic is used to produce hollow bricks which are manufactured in enormous quantities in Spain. They also constitute a major fraction of construction and demolition waste. The aim of this research was to investigate the properties and microstructure of alkali-activated cement pastes and mortars produced using red clay brick waste. The work shows that the type and concentration of alkali activator can be optimised to produce mortar samples with compressive strengths up to 50MPa after curing for 7days at 65°C. This demonstrates a new potential added value reuse application for this important waste material.