Effect of silica fume and glass powder for enhanced impact resistance in GGBFS-based ultra high-performance geopolymer fibrous concrete:An experimental and statistical analysis

Solid waste recycling is an economically sound strategy for preserving the environment,safeguarding natural resources,and diminishing the reliance on raw material consumption.Geopolymer technology offers a significant advantage by enabling the reuse and recycling of diverse materials.This research assesses how including silica fume and glass powder enhances the impact resistance of ultra-high-performance geopolymer concrete(UHPGC).In total,18 distinct mixtures were formulated by substituting ground granulated blast furnace slag with varying proportions of silica fume and glass powder,ranging from 10%to 40%.Similarly,for each of the mixtures above,steel fibre was added at a dosage of 1.5%to address the inherent brittleness of UHPGC.The mixtures were activated by combining sodium hydroxide and sodium silicate solution to generate geopolymer binders.The specimens were subjected to drop-weight impact testing,wherein an examination was carried out to evaluate various parameters,including flowability,density at fresh and hardened state,compressive strength,impact numbers indicative of cracking and failure occurrences,ductility index,and analysis of failure modes.Additionally,the variations in the impact test outcomes were analyzed using the Weibull distribution,and the findings corresponding to survival probability were offered.Furthermore,the microstructure of UHPGC was scrutinized through scanning electron microscopy.Findings reveal that the specimens incorporating glass powder exhibited lower cracking impact number values than those utilizing silica fume,with reductions ranging from 18.63%to 34.31%.Similarly,failure impact number values decreased from 8.26%to 28.46%across glass powder contents.The maximum compressive and impact strength was recorded in UHPGC,comprising 10%silica fume with fibres.

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%.

Frost Resistance of Pervious Concrete Mixed with Waste Glass Powder

The contents of waste glass powder(WGP)(0%,10%,15%,20%,25%)and water-binder ratio(W/C)(0.24,0.26,0.28)were used as influencing factors,and the quality loss rate(Δm)and compressive strength loss rate(Δfc)were used as characterization parameters.The Ca/Si ratio and main element contents of C-S-H gels with different WGP content were investigated by energy dispersive spectrometry(EDS).The pore structure evolution characteristics of WGP composite cementing materials were investigated by low field nuclear magnetic resonance(NMR).UsingΔfc as the index of frost resistance degradation and Weibull function,the frost resistance degradation of glass doped pervious concrete(WGP-PC)was modeled.The results show that,with WGP,for the same number of cycles,Δm andΔfc decrease and increase with the increase of WGP.Under the same WGP content,Δm andΔfc decrease first and then increase with the increase of W/C.After 100 freeze-thaw cycles,the samples with WGP content of 20%and W/C of 0.26 have the best freeze-resistance.Microscopic tests show that with the increase of WGP content,the Ca/Si ratio of C-S-H gel decreases at first and then increases with the increase of WGP content.The extreme value of Ca/Si is 2.36 when WGP is added by 20%.The pore volume of hardened paste with 20%WGP content decreased by 18.6%compared with that of cement system without WGP.The overall compactness of the specimen was improved.On the basis of the test data,a life prediction model was established according to Weibull function.The experiment showed thatΔfc could be used as a durability degradation index,and the slope of the reliability curve became gentle after WGP was added,which reduced the damage degradation rate of PC.W/C was 0.26.It's about 5000 hours.

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.

Strength and Microstructure of Mortar Containing Glass Powder and/or Glass Aggregate

The compressive strength of mortar containing glass powder（GP） and/or glass aggregate（GA） was tested, and its microstructure was also studied by thermogravimetric and differential thermal analysis（TG-DTA）, scanning electron microscopy（SEM）, energy dispersive spectroscopic analysis（EDX）, and X-ray diffraction（XRD） techniques. The incorporation of GA would decrease the compressive strength of the mortar in the absence of GP. Incorporating both GA and GP could change the hydration environment, promote pozzolanic reaction of GP and improve the compressive strength. GP does not lead to but can effectively control ASR（Alkali Silica Reaction）. GP and GA do not transform the type of hydrates, but have a great influence on the amounts of hydration products, and generate more calcium silicate hydrate（C-S-H gel） with lower Ca/Si ratio. GP and GA with good gradation will make the microstructure denser.

Effect of Glass Powder on Concrete Sustainability

As defined by the American Concrete Institute (ACI), alternative supplementary cementitious materials (ASCMs) and local materials are very important in concrete sustainability. As an ASCM, glass powder (GP) shows excellent pozzolanic properties. This paper focuses on characterization and the effect of GP on concrete properties compared to those of Class F fly ash (FFA) and ground granulated blast furnace slag (GGBS). Concrete incorporating 0, 20 and 30% of GP and other concrete mixes containing 30% of FFA or GGBS were cast. The concrete mixes considered in this study have water to binder (w/b) mass ratio ranging from 0.35 to 0.65. The mechanical properties such as compressive strength and durability including chloride ions permeability and chloride ions diffusion are evaluated. The results show that GP develops effects on mechanical properties similar to those of FFA and performs better than GGBS and FFA in terms of permeability reduction. GP reduces dramatically chloride permeability of concrete regardless w/b ratio, favoring an improvement of the concrete durability. Because of the interesting permeability developed by concretes incorporating GP, its use as an ASCM is promising.

Effect of Sand Partial Substitution for Glass Powder on the Behaviour of Sand-Cement Mortar

Partial substitution of aggregates for pieces of glass in concrete contributes to reducing the use this resource and preserving the environment for future generations. However, concretes or mortars mixed with crushed glass can deteriorate within a few years, because of the alkali-silica reaction related to the size of glass pieces. Some investigations were carried out in order to find out how to bring down this phenomenon. Different percentages of glass powder were mixed with mortar made from sand, cement and crushed glass pieces of which diameter is between 1 and 5 mm. Products obtained were submitted to flexural testing, compressive strength testing and resistance to acid attack and Scanning Electron microscopy (SEM) observations were made after a period running from 28 to 180 days of drying. The results show an increase in the mechanical properties of products with glass powder and an improvement in the durability of mortar in acidic environment. Such improvements are related to the enhanced adhesion created between crushed glass pieces and cementitious matrix containing glass powder as a result of pozzolanic reaction.

Reactivity of Recycled Glass Powder in a Cementitious Medium

The reactivity of the recycled glass powder (GP) in a cementitious medium has been studied over time by means of X-ray diffraction and thermal gravimetric analysis. Two different mixtures based on cement/glass powder (0 or 20 wt% GP) and lime/glass powder (70 wt% GP) were considered. Analysis revealed the coexistence of both hydration and pozzolanic reaction during the hardening of the mortars. At young age, the cement hydration would prevail over the pozzolanic one resulting in a decrease of physico-chemical and mechanical properties of the material due to the dilution effect. The pozzolanic reaction that predominates from 91 days, would induce the formation of supplementary C-S-H leading to improve the material properties.

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.

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.

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.

Effects of Wood Ash and Waste Glass Powder on Properties of Concrete in Terms of Workability and Compressive Strength in Jaresh City

The potential for using fly ash as a supplementary cementing material in concrete has been known almost since the beginning of the previous century. Fly ash was used as a supplementary cementing material (SCM) in the production of Portland cement concrete. A supplementary cementing material, when used in conjunction with Portland cement, contributes to the properties of the hardened concrete through hydraulic or pozzolanic activity, or both. In this study, the fly ash and waste glass powder were used in concrete blocks to study the improvement of concrete in terms of workability and strength. Therefore, an experimental study will be conducted to measure the engineering properties of cured concrete. In this research, local raw material from Jaresh area was used.

PHLOGOPITE GLASS CERAMIC BY POWDER SINTERING PROCESS

Phlogopite glass ceramics can be made by powder sintering technology. This paper now studies the factors which affect properties of the sintered phlogopite glass ceramic by X-ray diffraction in qualitative and quantitative way, and discusses the method improved the machinable properties of phlogopite glass ceramic. (Author abstract)

Study on the Physical and Mechanical Properties of Al-Powder Reinforced Bioactive Glass: Ceramic Composite Material

Glass-ceramic samples, having composition of SiO2-35, CaO-45, Na2O-10 and P2O5-10 in weight ratio were prepared through sintering route. Glass powder was reinforced by Al powder. The strength of glass-ceramic composite was found to be temperature dependent, and it varies with the addition of Al powder. Flexural strength increases with the increase of powder addition and sintering temperature, however, decreases with the increase of sintering time. There is an optimum temperature (>1100℃) above which flexural strength of all samples decreases. Bulk density changes to a higher value as the addition of Al-powder increases up to 3% by weight above which density decreases slowly. On the other hand, apparent porosity and water absorption decrease with the increase of percentage of Al powder added. Porosity and water absorption also showed a dependent characteristic on sintering time and sintering temperature.

碱激发废玻璃粉对水泥胶砂力学性能及微观结构的影响

研究了废玻璃粉(WGP)和碱激发剂NaOH掺量对胶砂抗压和抗折强度的影响,并分析了微观结构。结果表明:与纯水泥胶砂试件相比,当体系中未掺NaOH时,WGP的掺入降低了胶砂的抗压和抗折强度;在体系中掺入适量NaOH可有效提高掺WGP胶砂的120 d抗压和抗折强度;各组胶砂试件中均包含方解石、AFt、氢氧化钙(CH)、C-S-H等物相,其中,掺WGP胶砂试件中还包含C-A-S-H;N0组试件中的裂缝数量较少、尺寸较大,N1组、N3组试件呈多缝开裂特征,且裂缝尺寸相对较小;较低NaOH掺量胶砂试件中的C-(A)-S-H呈细长纤维状,较高NaOH掺量胶砂试件中的C-(A)-S-H呈多细孔珊瑚状;在适宜的NaOH掺量下,WGP活性被激发,参与了体系的水化反应。

磷酸钾镁水泥基涂料浆体抗NaCl溶液的侵蚀能力

磷酸钾镁水泥基(MKPC)涂料浆体经NaCl溶液和水长期浸泡后,测试了其强度、吸水率、物相组成和微结构的变化.结果表明:经NaCl溶液浸泡540 d后,MKPC涂料浆体试件的抗折和抗压强度剩余率明显高于经水浸泡后的试件,排除水腐蚀的因素后,NaCl溶液对MKPC硬化体有增强作用;经硅微粉和水玻璃改性的MKPC涂料浆体试件抗折和抗压强度剩余率均高于未改性试件,水玻璃和硅微粉的改性能够改善MKPC硬化体对NaCl溶液的抗侵蚀性能;在水和NaCl溶液中浸泡540 d后,经硅微粉和水玻璃改性的MKPC涂料浆体试件孔结构劣化程度较未改性试件明显减轻.

钼尾矿基多固废协同制备发泡陶瓷

为了提高固废在制备发泡陶瓷中的利用率,利用不同固废的特性协同制备发泡陶瓷。以钼尾矿为主要原料,粉煤灰、废玻璃粉和白云石为辅料,SiC为发泡剂制备发泡陶瓷。研究了粉煤灰、废玻璃粉和白云石的添加量对样品外观形貌、孔径、气孔率、体积密度、抗压强度的影响,并分析其影响机理。结果表明,最佳组分为52.5%钼尾矿,25%粉煤灰,15%废玻璃粉,7.5%白云石,此条件下发泡陶瓷体积密度为0.519 g/cm^(3),气孔率为62.96%,抗压强度为9.666 MPa。加入粉煤灰可促使长石类矿物的生成,其与石英交织,制备出的发泡陶瓷质轻高强,可用作建筑中的轻质隔墙板。

Influence of aluminium nitride as a foaming agent on the preparation of foam glass-ceramics from high-titanium blast furnace slag

To effectively reuse high-titanium blast furnace slag （TS）, foam glass-ceramics were successfully prepared by powder sintering at 1000℃. TS and waste glass were used as the main raw materials, aluminium nitride （AIN） as the foaming agent, and borax as the fluxing agent. The influence of the amount of A1N added （lwt%-5wt%） on the crystalline phases, microstructure, and properties of the produced foam glass-ceramics was studied. The results showed that the main crystal phases were perovskite, diopside, and augite. With increasing A1N content, a transformation from diopside to augite occurred and the crystallinity of the pyroxene phases slightly decreased. Initially, the aver- age pore size and porosity of the foam glass-ceramics increased and subsequently decreased; similarly, their bulk density and compressive strength decreased and subsequently increased. The optimal properties were obtained when the foam glass-ceramics were prepared by adding 4wt% AIN.

RESEARCH ON FACTORS AFFECTING THE COLOURATION OF RED GLASS-CERAMICS

In this pater, effect of alkali, zinc oxide and colorants such as cadmiun sulfide and selenium powder on the colouration of the red glass-ceramic materials in the CaO-Al2O3-SiO2 system has been studied. The relevant laws have been presented and analyzed.

PREPARATION AND CHARACTERIZATION OF SILICA GEL POWDERS

Silica gel powders,with particle diameter in the range 10 to 20 nm,were prepared from water glass using ethyl acetate as a latent acid reagent. The products were characterized by TGDTA, TEM, FTIR, BET and some other experiment methods. The process of silica solgel formation and the thermal behavior as well as phase change of the silica powders during heattreating process were studied, and the effect of heattreating temperature on the specific surface area and apparent density of the silica powders was investigated.