Optimization of Mortar Compressive Strength Prepared with Waste Glass Aggregate and Coir Fiber Addition Using Response Surface Methodology

Waste Glass(WGs)and Coir Fiber(CF)are not widely utilized,even though their silica and cellulose content can be used to create construction materials.This study aimed to optimize mortar compressive strength using Response Surface Methodology(RSM).The Central Composite Design(CCD)was applied to determine the optimization of WGs and CF addition to the mortar compressive strength.Compressive strength and microstructure testing with Scanning Electron Microscope(SEM),Fourier-transform Infrared Spectroscopy(FT-IR),and X-Ray Diffraction(XRD)were conducted to specify the mechanical ability and bonding between the matrix,CF,and WGs.The results showed that the chemical treatment of CF produced 49.15%cellulose,with an average particle size of 1521μm.The regression of a second-order polynomial model yielded an optimum composition consisting of 12.776%WGs and 2.344%CF with a predicted compressive strength of 19.1023 MPa.C-S-H gels were identified in the mortars due to the dissolving of SiO_(2) in WGs and cement.The silica from WGs increased the C-S-H phase.CF plays a role in preventing,bridging,and branching micro-cracks before reaching maximum stress.WGs aggregates and chemically treated CF are suitable to be composited in mortar to increase compressive strength.

Construction utilization of foamed waste glass

Foamed waste glass(FWG) material is newly developed for the purpose to utilize the waste glassware and other waste glass. FWG has a multi-porous structure that consists of continuous or discontinuous voids. Hence lightweight but considerable stiffness can be achieved. In the present study, the manufacture and engineering properties of FWG are introduced first. Then, the utilizations of FWG are investigated in laboratory tests and field tests. Some case studies on design and construction work are also reported here. Through these studies we know that the discontinuous void material can be utilized as a lightweight fill material, ground improvement material and lightweight aggregate for concrete. On the other hand, the continuous void material can be used as water holding material for the greening of ground slope and rooftop, and as clarification material for water.

Study on Factors Affecting Properties of Foam Glass Made from Waste Glass

Foam glass is a new green material to make use of waste glass and is popular for its energy-saving and light weight features.The problems in the current study of foam glass is that its properties require improvement to match the growing demands of application specific standards.Properties of foam glass is related to its porous structure,which is affected by various factors.The influence of raw material component,foaming agents and sintering system on the porous structure and properties of foamed glass is studied.Density decreases with the decrease of quartz and barite content.Thermal conductivity is more affected by barite content,and the lowest thermal conductivity is obtained when 10%quartz and 6%borax are added.Compressive strength is more affected by borax content,and the highest compressive strength is obtained when 5%quartz,10%barite and 6%borax are added.Foam glass samples with different porous structures and improved properties are obtained using graphite and CaCO3 as foaming agents.Compared with the soldcommercial foam glass for thermal insulation materials,the compressive strength of samples prepared by using compound foaming agents is increased by a factor of 2–3 times higher.With porous structure and properties adjusted by the optimization of raw materials and foaming agent,there exists the potential for factories to produce foam glass with expanded application scope.

Effect of Mitigating Strength Retrogradation of Alkali Accelerator by the Synergism of Sodium Sulfate and Waste Glass Powder

This work aims to utilize waste glass powder(WGP)as a plementary material to mitigate the strength shrinkage caused by the alkaline accelerator.Waste glass power was used to replace cement by 0%,10%,and 20%to evaluate waste glass powder on the alkaline accelerator’s strength retrogradation.The results show that the strength improvement effect of unitary glass powder is inconspicuous.Innovative methods have been proposed to use sodium sulfate and waste glass powder synergism,using the activity of amorphous silica in glass powder.Compared with the reference group,the compressive strength of 28d mortar increases by 67%when the sodium sulfate content is 2.5%,and the replacement amount of waste glass powder is 10%.Besides,XRD and SEM analysis of hydration products also confirmed that the synergistic effect of sodium sulfate and waste glass powder could reduce strength inversion.The findings presented in this paper are pivotal for using waste glass to solve the problem of strength inversion caused by the alkaline accelerator.

Mechanical Properties and Solidified Mechanism of Tailings Mortar with Waste Glass

In order to improve the comprehensive utilization of solid waste such as iron tailings and waste glass and so on,mechanical property test of cement tailings mortar mixed waste glass and curing mechanism research were conducted in the key materials mechanics lab of Liaoning province.The experimental results show that adding waste glass particles can improve the grain size distribution of tailings.The effect is proportional to the content.The compressive strength of tailings mortar has increased significantly.The fineness modulus of tailings mortar mixture adding waste glass powder was gradually reducing with the increase of the dosage of waste glass powder,but the compressive strength of the mixture has gradually enhanced with the increase of the dosage.Microscopic analysis shows that the waste glass particles in the mortar mainly play a role of coarse aggregate and glass powder after grinding fine below a certain size shows strong volcanic activity,which can act hydration with tailings,at the same time glass powder also,plays a role in fine aggregate filling.Therefore,all of glass particles and glass powder can be used as the additive material for improving and optimizing the mechanical property of tailings mortar.

Influence of Ultra Fine Glass Powder on the Properties and Microstructure of Mortars

This study focuses on the effect of ultrafine waste glass powder on cement strength,gas permeability and pore structure.Varying contents were considered,with particle sizes ranging from 2 to 20μm.Moreover,alkali activation was considered to ameliorate the reactivity and cementitious properties,which were assessed by using scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDS),and specific surface area pore size distribution analysis.According to the results,without the addition of alkali activators,the performance of glass powder mortar decreases as the amount of glass powder increases,affecting various aspects such as strength and resistance to gas permeability.Only 5%glass powder mortar demonstrated a compressive strength at 60 days higher than that of the control group.However,adding alkali activator(CaO)during hydration ameliorated the hydration environment,increased the alkalinity of the composite system,activated the reactivity of glass powder,and enhanced the interaction of glass powder and pozzolanic reaction.In general,compared to ordinary cement mortar,alkali-activated glass powder mortar produces more hydration products,showcases elevated density,and exhibits improved gas resistance.Furthermore,alkali-activated glass powder mortar demonstrates an improvement in performance across various aspects as the content increases.At a substitution rate of 15%,the glass powder mortar reaches its optimal levels of strength and resistance to gas permeability,with a compressive strength increase ranging from 28.4%to 34%,and a gas permeation rate reduction between 51.8%and 66.7%.

Silica Gel from Chemical Glass Bottle Waste as Adsorbent for Methylene Blue:Optimization Using BBD

This research focuses on the effective removal of methylene blue dye using silica gel synthesized from chemical glass bottle waste as an environmentally friendly and cost-effective adsorbent.The adsorption process was optimized using Box-Behnken Design(BBD)and Response Surface Methodology(RSM)to investigate the influence of pH(6;8 and 10),contact time(15;30 and 45 min),adsorbent mass(30;50 and 70 mg),and initial concentration(20;50 and 80 mg/L)of the adsorbate on the adsorption efficiency.The BBD was conducted using Google Colaboratory software,which encompassed 27 experiments with randomly assigned combinations.The silica gel synthesized from chemical glass bottle was characterized by XRD,FTIR,SEM-EDX and TEM.The adsorption result was measured by spectrophotometer UV-Vis.The optimized conditions resulted in a remarkable methylene blue removal efficiency of 99.41%.Characterization of the silica gel demonstrated amorphous morphology and prominent absorption bands characteristic of silica.The Langmuir isotherm model best described the adsorption behavior,revealing chemisorption with a monolayer coverage of methylene blue on the adsorbent surface,and a maximum adsorption capacity of 82.02 mg/g.Additionally,the pseudo-second-order kinetics model indicated a chemisorption mechanism during the adsorption process.The findings highlight the potential of silica gel from chemical glass bottle waste as a promising adsorbent for wastewater treatment,offering economic and environmental benefits.Further investigations can explore its scalability,regenerability,and reusability for industrial-scale applications.

Characterization of Wollastonite Glass-ceramics Made from Waste Glass and Coal Fly Ash

The crystallization behavior of wollastonite glass-ceramics was investigated by means of X-ray diffraction （XRD） analysis and surface morphological observations, and the chemical compositions were evaluated by field emission-scanning electron microscopy （FE-SEM） and energy dispersive X-ray spectroscopy （EDS）. Various heat treatment temperatures （850, 900, 950, 1000 and 1050 ℃） were used to obtain glass-ceramics of the ideal wollastonite crystal phase as well as optimum mechanical properties and chemical durability. From XRD, FE-SEM and EDS, the crystallization of acicular crystal phase in the matrix was achieved at heat treatment temperature of 1000 and 1050 ℃, and wollastonite （CaSiO3） was found in the acicular type main crystal phase in the glass-ceramics. Various properties, such as density, compressive strength, bending strength and chemical durability were also examined. The mechanical properties of glass-ceramics obtained at the heat treatment temperature of 1000 and 1050 ℃ were superior to those obtained at the heat treatment temperature of 850 ℃.

Recycling of waste glass as aggregate in cement-based materials

Glass is a common material made from natural resources such as sand.Although much of the waste glass is recycled to make new glass products,a large proportion is still being sent to landfill.Glass is a useful resource that is non-biodegradable,occupying valuable landfill space.To combat the waste glass that is heading to landfill,alternative recycling forms need to be investigated.The construction industry is one of the largest CO_(2) emitters in the world,producing up to 8% of the global CO_(2) to produce cement.The use of sand largely depletes natural resources for the creation of mortars or concretes.This review explores the possibilities of incorporating waste glass into cement-based materials.It was found waste glass is unsuitable as a raw material replacement to produce clinker and as a coarse aggregate,due to a liquid state being produced in the kiln and the smooth surface area,respectively.Promising results were found when incorporating fine particles of glass in cement-based materials due to the favourable pozzolanic reaction which benefits the mechanical properties.It was found that 20% of cement can be replaced with waste glass of 20 mm without detrimental effects on the mechanical properties.Replacements higher than 30% can cause negative impacts as insufficient amounts of CaCO_(3) remain to react with the silica from the glass,known as the dilution effect.As the fine aggregate replacement for waste glass increases over 20%,the mechanical properties decrease proportionally;however,up to 20% has similar results to traditionally mixes.

Experimental Evaluation of Compressive Strength and Gas Permeability of Glass- Powder-Containing Mortar

Glass powder of various particle sizes(2,5,10 and 15μm)has been assessed as a possible cement substitute for mortars.Different replacement rates of cement(5%,10%,15%,and 20%)have been considered for all particle sizes.The accessible porosity,compressive strength,gas permeability and microstructure have been investigated accordingly.The results have shown that adding glass powder up to 20%has a significantly negative effect on the porosity and compressive strength of mortar.The compressive strength initially rises with a 5%replacement and then decreases.Similarly,the gas permeability of the mortar displays a non-monotonic behavior;first,it decreases and then it grows with an increase in the glass powder content and particle size.The porosity and gas permeability attain a minimum for a 5%content and 10μm particle size.Application of a Nuclear magnetic resonance(NMR)technique has revealed that incorporating waste glass powder with a certainfineness can reduce the pore size and the number of pores of the mortar.Compared with the control mortar,the pore volume of the waste glass mortar with 5%and 10μm particle size is significantly reduced.When cement is partially replaced by glass powder with a particle size of 10μm and a 5%percentage,the penetration resistance and compressive strength of the mortar are significantly improved.

Early-Age Properties Development of Recycled Glass Powder Blended Cement Paste:Strengths,Shrinkage,Nanoscale Characteristics,and Environmental Analysis

Recycling solid waste in cement-based materials cannot only ease its load on the natural environment but also reduce the carbon emissions of building materials.This study aims to investigate the effect of recycled glass powder(RGP)on the early-age mechanical properties and autogenous shrinkage of cement pastes,where cement is replaced by 10%,20%and 30%of RGP.In addition,the microstructure and nano-mechanical properties of cement paste with different RGP content and water to binder(W/B)ratio were also evaluated using SEM,MIP and nanoindentation techniques.The results indicate that the early-age autogenous shrinkage decreases with the increase of RGP content and W/B ratio.While the mechanical strength deteriorates due to the addition of RGP,it can be compensated by reducing the W/B ratio.Although the addition of RGP increases the total porosity of the hardened paste,it reduces the small size porosity(<50 nm).In addition,the proportions of different types of C-S-H are changed,and the volume fraction of porosity is increased,but that of hydration products of cement paste is reduced due to the incorporation of RGP.Besides its pozzolanic activity,the mitigated shrinkage deformation that RGP is generating in cement pastes is encouraging for its use as a novel supplementary cementitious material that reduces the early-age cracking risk of cement-based materials.Meanwhile,the life cycle assessments indicate that the RGP-cement component is an economical and eco-friendly novel engineering material.

Preparation and Study of Borosilicate Foam Glass with High Thermal Insulation and Mechanical Strength

Foam glass is a kind of green building material that is widely used because of its excellent thermal insulation and mechanical properties.In this study,the borosilicate foam glass was fabricated by powder sintering method using recycled soda lime waste glass,quartz,and borax as the primary raw materials.CaCO_(3)was used as a foaming agent and Na_(2)CO_(3)as a flux agent.Results showed that as the quartz content decreases from 30 to 17.5 wt.%and borax content increases from 5 to 17.5 wt.%,the pore size,porosity,and thermal insulation of borosilicate foam glass increase significantly,while the compressive strength decreases slightly.When the content of quartz and borax are both 17.5 wt.%,borosilicate foam glass with outstanding performance can be prepared,whose pore distribution is uniform,mean pore size is 1.93 mm,total porosity is 83.44%,thermal conductivity is 0.0711W/(m⋅K),and compressive strength is 2.37 MPa.Finally,the influences of foaming agent content,flux agent content,foaming temperature,and holding time on the pore structure and various properties of borosilicate foam glass were investigated by orthogonal test.According to the results,the foaming temperature has a significant effect,and appropriate foaming agent content,flux agent content,and holding time help to form a uniform pore structure,thereby improving the thermal insulation and mechanical strength of the borosilicate foam glass.

Identification of Glass Powders and Sands from the Crushing of Glass Waste from the City of Loméin Togo

The sustainability of a city depends on the effective and efficient management of its solid waste. Waste recycling channels mainly process glass bottles for direct reuse. Some of these sectors carry out the crushing and grinding of end-of-life glass waste for use in civil engineering without the identification in terms of building materials being clearly established. The present study therefore aims to determine the physical and chemical characteristics of glass powders and sands resulting from the crushing and grinding of glass waste from Grand Lomé in Togo in order to consider their granular potential. Samples of sand and glass powder from the crushing and grinding of white, brown and green glass were subjected to characterization tests in the laboratory followed by analysis of the granular parameters and their modeling by Weibull’s law. The results show that the powder and the glass sand contain a high proportion of silica (SiO2) ranging from 69.11% to 70.18% and a low proportion of alumina (Al2O3) (less than 0.07) and iron (Fe2O3) (lower to 1.09). These three materials have tight and male graded grain sizes (Cu Cc omogeneous (k < 2.89). The absolute density (2 dab < 3) and the fineness modulus (Mf 2.1) make these materials probable aggregates for plaster and coating mortars. Nevertheless, an in-depth study will be made to determine a suitable formula.

Experimental Study of the Physical and Mechanical Behaviour of Mortar Formulations with Fine Sands of Recycled Glass

This work is part of an experimental contribution approach to the study of the incorporation of glass sand from the grinding of recycled glass waste in cement mortars and its influence on the physical and mechanical behavior of semi-rich mortars without adjuvants. For this purpose, after a physical characterization of the sands, eight (08) formulations of mortars based on cement CEM II B/L 32.5R and fine sands (0/2) of glass at mass contents of 0%, 10%, 20%, 30%, 40%, 50%, 75% and 100% of the silty sand (0/2) were made respectively to three (03) types of fine glass sand (white, brown, green) with water dosages on cement (W/C) of 0.50, 0.45, 0.40. The results obtained show that the fine sands of recycled glass have a higher water absorption than the silty sand and the physical properties of the mortars prepared are affected by the increase in the glass content. The mechanical performances are obtained for the ratio W/C = 0.50 and the formulation of glass mortars for an optimal compressive strength superior to glass-free mortar requires a substitution of 10% for fine white glass sand, 20% for sand fine green glass and 75% for fine brown glass sand. The comparative study between these different compositions of fine glass sand mortars shows that the mechanical performances of fine brown glass sand are better than other glass sands but generally remain inferior to the control mortar based on natural silty sand.

Effect of Glass Powder on Chloride Ion Transport and Alkali-aggregate Reaction Expansion of Lightweight Aggregate Concrete

The effects of glass powder on the strength development, chloride permeability and potential alkali-aggregate reaction expansion of lightweight aggregate concrete were investigated. Ground blast furnace slag, coal fly ash and silica fume were used as reference materials. The re- placement of cement with 25% glass powder slightly decreases the strengthes at ？ and 28 d, but shows no effect on 90 d＇s. Silica fume is very effective in improving both the strength and chloride penetration resistance, while ground glass powder is much more effective than blast furnace slag and fly ash in improving chloride penetration resistance of the concrete. When expanded shale or clay is used as coarse aggregate, the concrete containing glass powder does not exhibit deleterious expansion even if alkali-reactive sand is used as fine aggregate of the concrete.

Design and evaluation of glasphalt mixtures by using recycled waste cullet

A glass crusher was developed to improve the waste glass crushing process.The waste glass was recycled,crushed and sieved to different particle sizes as glass aggregates,and the surface of glass aggregates was treated by nano-Fe2O3 suspension to improve the anti-striping property.The glasphalt mixture made by partly replacing mineral aggregates with glass aggregates was designed and evaluated.The sizes of glass aggregates were selected to be 2.36 and 4.75 mm,and the optimum concentration of nano-Fe2O3 suspension was determined to be 10%.The optimum asphalt content(OAC)was determined by the Marshall method and the glass aggregate content.The influence of the glass aggregate content on the technical properties of glasphalt mixtures were analyzed by the rutting test,three-point bending test,freeze-thaw splitting test and skid resistance test.The results show that the optimal content of glass aggregates and OAC are recommended to be 15%and 4.4%,respectively.These environmentally-friendly glasphalt mixtures can solve the problem of environmental pollution caused by waste glass,as well as reducing the cost of pavement materials and construction.