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.

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.

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.

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.

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.

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.

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.

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.

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.

Performance improvement of a crumb rubber modified bitumen using recycled glass powder

In this study, the efficiency of bitumen and asphalt mixtures modified with crumb rubber(CR) and recycled glass powder(RGP) is evaluated. From an environmental point of view, the application of RGP in asphalt mixtures is considered beneficial since it prevents accumulation of waste glass in the natural environment. Rheological and mechanical properties of modified bitumen samples were investigated by laboratory methods such as bitumen conventional tests and dynamic shear rheometer(DSR), and also by asphalt mixture performance tests including Marshall stability, indirect tensile strength(ITS),compressive strength, and indirect tensile stiffness modulus. The results showed that the application of RGP in place of CR has no negative impact on the efficiency of bitumen and asphalt mixtures and even improves their engineering properties except for the toughness index(TI). Moreover, a modification with 5% CR and 5% RGP in asphalt mixtures results in the best overall performance.

Influence of Recycling Waste Glass as Fine Aggregate on the Concrete Properties

Recent years have witnessed an increase in the quantity of waste glass(WG)across the globe.Replacing the fine aggregate with WG is one of the steps toward preserving the natural resources of the environment and creating low-cost concrete.The present study is concerned with replacing fine aggregates with glass powder(GP)at(0%,15%,30%,and 50%).It has studied the fresh and hardened properties(compressive strength,tensile strength,hardened density,and slump)for all the mentioned percent replacements.The findings have shown that all mixtures containing GP gave acceptable slump results within the design limits(2–5 cm)according to ACI standard 211.1.It has been observed that increasing the proportion of GP led to a decrease in the weight of concrete.Lastly,replacing GP with sand by 30%has led to an increase in the compressive strength by about 2.4%and 12.45%,and the tensile strength by about 2.5%and 26.54%at 7-and 28-d,respectively in comparison to normal concrete.

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.

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)

废弃玻璃粉风积沙混凝土柱抗震性能试验研究

为研究玻璃粉等质量取代20%水泥与风积沙等质量取代30%天然砂对混凝土柱抗震性能的影响,本文设计和制作4根混凝土柱试件。第1根是普通混凝土柱,第2根是玻璃粉等质量取代20%水泥的混凝土柱,第3根是风积沙等质量取代30%河砂的混凝土柱,第4根是同时用玻璃粉和风积沙分别等质量取代20%水泥和30%河砂的混凝土柱。通过低周往复荷载试验,对比分析各个试件的破坏形态、承载力、滞回性能、骨架曲线、耗能能力、延性系数、刚度退化规律和变形特点。结果表明:20%取代率的玻璃粉取代水泥和30%取代率的风积沙取代天然河砂均能提高混凝土柱的抗震性能,降低构件破坏程度;基于试验结果、Fajfar和Park-Ang提出的地震损伤模型,对其耗能因子β进行修正,得到了修正后的Park-Ang损伤模型,并与废弃玻璃粉风积沙混凝土柱的试验过程吻合较好。

添加复合稀释剂的低爆速乳化炸药的制备及性能

以玻璃微球和滑石粉共同作为稀释剂制备一种低爆速乳化炸药。观察不同质量分数的玻璃微球和滑石粉对乳化炸药形貌的影响,并对乳化炸药的爆速、猛度、空中爆炸冲击波压力及储存稳定性进行测试。实验结果表明,随着滑石粉质量分数的增加,乳化炸药的形貌由乳胶状逐渐向颗粒状转化,爆速呈线性下降,对玻璃微球质量分数为5%、10%、15%的乳化炸药,测得最低爆速分别为3440、2740、2188 m/s。而随着滑石粉质量分数的增加,猛度、空中爆炸冲击波峰值超压均呈非线性下降,当滑石粉控制在一定量时,冲击波正压作用时间变化不大,乳化炸药储存稳定性较好。这种低爆速乳化炸药成本低廉、爆轰性能可调、储存稳定性好,具有较好的实用性。

m(ZnO)/m(B_(2)O_(3))质量比对低熔点封接玻璃Bi_(2)O_(3)-B_(2)O_(3)-ZnO结构、性能与润湿性的影响

针对真空玻璃封接的性能要求,本文采用高温熔融法制备了一种针对真空玻璃封接的铋系非晶无铅玻璃粉,通过高温X射线衍射、粉末X射线衍射、拉曼光谱、差式扫描量热仪、热膨胀测试和扫描电子显微镜等测试方法,研究了m(ZnO)/m(B_(2)O_(3))质量比对Bi_(2)O_(3)-B_(2)O_(3)-ZnO玻璃的网络结构、特征温度、热膨胀系数和封接温度的影响。结果表明,增加m(ZnO)/m(B_(2)O_(3))质量比可促进锌氧多面体由[ZnO_(4)]向[ZnO_(6)]转变,导致热膨胀系数降低,特征温度升高。当m(Bi_(2)O_(3))∶m(B_(2)O_(3))∶m(ZnO)质量比为80∶7∶13,玻璃具有较低的玻璃化转变温度T_(g)(371℃)和膨胀软化温度T_(f)(401℃),热膨胀系数为9.3×10^(-6)℃^(-1),封接温度为450℃,可满足真空玻璃封接对低熔点封接玻璃粉的要求。

废玻璃粉对泡沫混凝土性能和微观孔结构的影响及其价值工程分析

玻璃研磨成粉后的主要成分与粉煤灰相似,具备潜在的火山灰活性。为提高我国对废弃玻璃的循环利用率,将泡沫混凝土与废玻璃粉结合用于改善泡沫混凝土性能,减少水泥消耗量,提高废玻璃的循环利用率。本文研究了以废玻璃粉作为胶凝材料替代部分水泥,并探究废玻璃粉对泡沫混凝土抗压强度、干密度、干缩率、软化系数等的影响。结果表明:在替代胶凝材料总质量的0%~30%(质量分数,下同)时,废玻璃粉会提高泡沫混凝土的抗压强度;且在废玻璃粉掺量为20%时,泡沫混凝土28、56 d抗压强度达到最大值;而在120 d时,废玻璃粉掺量为30%的泡沫混凝土抗压强度达到最大值。废玻璃粉会降低泡沫混凝土的干缩值,且掺量越大,干缩值的降低程度越大,这有助于解决泡沫混凝土易开裂的问题。废玻璃粉能够明显提高泡沫混凝土的软化系数,便于其在潮湿或水下环境应用。此外,从微观孔结构的角度对废玻璃粉引起的泡沫混凝土力学及耐久性能的变化规律做出解释,最后对废玻璃粉引入泡沫混凝土后的价值进行分析,定量证明了废玻璃粉的环保性和经济性。

玻璃粉对陶瓷化PVC复合材料性能影响

探讨了玻璃粉用量对陶瓷化聚氯乙烯(PVC)复合材料性能的影响。结果表明,添加60份自制玻璃粉,PVC复合材料综合性能较好,材料硬度(邵氏D)可达41,氧指数达到30%。随着玻璃粉含量增大,复合材料内部孔洞变多自支撑力改变,在600℃烧蚀30 min后所形成的陶瓷体成瓷效果好,结构密实且强度高、自支撑能力强、内部孔洞少、瓷化作用明显。

不同替代率玻璃粉对混凝土性能的影响

废弃玻璃作为建筑废弃物对环境存在较大的危害,在混凝土中掺加玻璃粉,可以对废弃玻璃进行资源化有效利用,消解废弃玻璃对环境的污染。研究表明,混凝土中掺加玻璃粉,导致物料颗粒摩擦加大,玻璃粉替代率越高,混凝土工作性能越差,并且玻璃粉早期火山灰效应不明显,掺加玻璃粉将降低混凝土早期抗压强度,但随着龄期的增加,混凝土抗压强度增加。应用全生命周期评价方法分析表明,掺入适量的玻璃粉可以获得良好的环境效益与经济效益。

花岗岩粉体两步法烧结多孔微晶玻璃及其发泡机理研究

以花岗岩粉体为原料、以SiC为发泡剂,采用低温烧结—高温发泡的两步法烧结工艺,制备出多孔微晶玻璃。利用XRD、SEM、TG-DSC和陶瓷弯曲试验机等测试技术,系统研究烧结温度和发泡温度对多孔微晶玻璃的气孔结构、晶相组成、抗压强度的影响,并分析微晶玻璃发泡机理。随着烧结温度的升高,未添加发泡剂的微晶玻璃抗弯强度与体积密度均先增大后减小,最佳烧结温度为1120℃。随着发泡温度的升高,多孔微晶玻璃中钙长石和石英逐渐溶于玻璃相,结晶度降低,气孔孔径增大,表观密度和抗压强度均减小,但比强度在1220℃时达到最大值5.36 kN·m·kg^(-1)、气孔率为59.7%。与一步烧结的通孔结构不同,两步烧结形成闭孔结构,多孔微晶玻璃的比强度明显高于一步烧结法。