Controlled low-strength material incorporating recycled fine aggregate from urban red brick based construction waste

Sixteen controlled low-strength material( CLSM)mixtures with various cement-to-sand( C/Sa) ratios and water-to-solid( W/So) ratios were prepared using recycled fine aggregate from urban red brick based construction waste.The fluidity and bleeding of the fresh CLSM mixtures were measured via the modified test methods, and the hardened CLSM mixtures were then molded to evaluate their compressive strength and durability. The results showthat the fluidity of the fresh CLSM mixtures is 105 to 227 mm with the corresponding bleeding rate of 3. 7% to 15. 5%, which increases with the increase in fluidity. After aging for 28 d,the compressive strength of the hardened CLSM mixtures reaches 1. 15 to 13. 96 M Pa, and their strength can be further enhanced with longer curing ages. Additionally, the strength increases with the increase of the C/Sa ratio, and decreases with the increase of the W/So ratio under the same curing age. Based on the obtained compressive strength, a fitting model for accurately predicting the compressive strength of the CLSM mixtures was established, which takes into account the above two independent variables( C/Sa and W/So ratios).M oreover, the durability of the hardened CLSM mixtures is enhanced for samples with higher C/Sa ratios.

Properties of Rapid Hardening Controlled Low Strength Material Made of Recycled Fine Aggregate from Urban Red Brick Construction Waste

In some cases of emergency backfill engineering projects, traditional backfill materials cannot meet the requirements of fast construction due to their long curing time. This study presents a new kind of rapid hardening controlled low strength material, which utilizes both rapid hardening sulphoaluminate cement and recycled fine aggregate from urban red brick construction waste. Totally, sixteen mixtures were prepared for the experiment with different cement-to-sand ratios and water-to-solid ratios. The flowability and bleeding rate of fresh mixture were measured to evaluate its workability, and the compressive strength of hardened mixture was tested to evaluate its rapid hardening and mechanical properties. Test results indicate that rapid hardening controlled low strength material containing recycled fine aggregate from urban red brick construction waste can achieve the desirable flowability, but the bleeding rate increases with the increase of flowability. In addition, 2-hour compressive strength can reach 0.08 - 0.12 MPa, and 4-hour compressive strength is 0.32 - 1.54 MPa, which can meet the requirements of emergency backfill construction. At last, based on the derived compressive strength, a fitting model for predicting compressive strength evolution of this new rapid hardening backfill material is developed, which fits accurately with these experimental data.

Enhanced strength in novel nanocomposites prepared by reinforcing graphene in red soil and fly ash bricks

Low-dimensional nanomaterials such as graphene can be used as a reinforcing agent in building materials to enhance the strength and durability. Common building materials burnt red soil bricks and fly ash bricks were reinforced with various amounts of graphene, and the effect of graphene on the strength of these newly developed nanocomposites was studied. The fly ash brick nanocomposite samples were cured as per their standard curing time, and the burnt red soil brick nanocomposite samples were merely dried in the sun instead of being subjected to the traditional heat treatment for days to achieve sufficient strength. The water absorption ability of the fly ash bricks was also discussed. The compressive strength of all of the graphene-reinforced nanocomposite samples was tested, along with that of some standard (without graphene) composite samples with the same dimensions, to evaluate the effects of the addition of various amounts of graphene on the compressive strength of the bricks.

Investigation of the medium calcium based non-burnt brick made by red mud and fly ash: durability and hydration characteristics

Red mud is a type of highly alkaline waste residue produced in the process of alumina smelting by the Bayer process.Based on the idea of medium calcium content,solid wastes such as red mud and fly ash were used to prepare non-burnt bricks;and the mass ratio of CaO/SiO2 was selected in the range of 0.88–1.42.Mechanical properties and durability were investigated with a compressive strength test.X-ray diffractometry(XRD),scanning electron microscope(SEM),and Fourier transform infrared spectroscopy(FTIR)techniques were used to characterize the hydration characteristic.The environmental performance was analyzed by Inductively Coupled Plasma Mass Spectrometry(ICP).The results indicated that the mechanical properties and the durability were optimal when the mass ratio of CaO/SiO2 was 1.23.The hydration products were mostly C–S–H gel,ettringite,Na4Ca(Si10All6)O32·12H2O and Ca3Al2(SiO4)(OH)8.They were responsible for the strength development,and the CaO/SiO2 mass ratio of 1.23 had the best polymerized structure.The results of an environmental performance test showed that the heavy metals in the raw materials were well-solidified in the brick.Therefore,this paper provides an effective solution for use of solid wastes in building material.

Preparation and Reaction Mechanism of Red Mud based Ceramic Simple Bricks

In order to utilize solid wastes,ceramic simple bricks with high performances were made from industrial solid wastes such as red mud,fly ash and poor clay shale as main raw materials in this paper.The phase compositions and microstructures were tested by XRD,SEM and EPMA.The experimental results show that the water absorption is 45.64%,the porosity is 58.91%,bulk density is 1.29 g·cm-3,compressive strength is 54.91 MPa,bending strength is 29.52 MPa,freeze-thaw resistance is 29.28 MPa,specific heat capacity at constant pressure is 1.31 J·g-1·K-1,thermal diffusivity is 5.89×10-3 cm2·s-1,and thermal conductivity is 1.15×10-2 W·cm-1·K-1.These effects of additives and preparation process to the properties and microstructures were discussed in detail.The reaction mechanism was also discussed.The results of the reaction mechanism show that there has wollastonite and feldspar generated during the process of firing while Ca gathered around the feldspar,and then Ca would displace K and generated cacoclasite.

Evolution of Fire-sealing Gable Walls' Diversity in Leizhou Traditional Vernacular Red-brick Dwellings

Peculiar color and form of Leizhou red-brick folk dwelling distinguishes it from other vernacular dwellings in Lingnan region(south of the Five Ridges, referring to the current Guangdong and Guangxi). The fi re-sealing gable wall(hereinafter referred to as fi re-sealing wall) in brilliant colors, diversifi ed forms and exaggerated shapes is a remarkable symbol of local dwellings. Originating from Fulao traditional vernacular dwelling and inheriting its advantages, fi re-sealing wall of Leizhou red-brick vernacular dwelling has shown diversity for the infl uence of immigrants, regional cultures, social background and economic status, and formed its own features in color, form and decoration. On the basis of fi eld investigation, this paper described diversifi ed features of the fi re-sealing wall of Leizhou red-brick vernacular dwelling, analyzed the causes of its diversity from the perspectives of aesthetics, function and technology, and explored the harmonious living philosophy implied by its function, form and art.

闽南沿海红砖民居屋顶构造工艺研究

闽南沿海红砖民居的屋顶多以红瓦覆盖,在当地自然、人文等因素的影响下,发展出独具地域特色的形态特征和构造工艺,蕴含着深厚的建构思想与营造智慧。文章采用田野调研、匠师访谈等方法,从屋顶各部位的构造特征入手,归纳材料种类、尺寸与砌筑方式,探究其设计规律与原理,梳理构造做法的地域差异,总结构造设计与防雨、排水、抗风等实用功能的关联,以期为今后的相关研究以及遗产保护工作提供参考。

氧化石墨烯对再生混凝土抗压强度的影响

研究了氧化石墨烯(GO)的掺量(0、0.042%、0.063%、0.084%、0.105%)对不同再生粗骨料取代率(0、40%、60%、80%、100%)再生混凝土试件抗压强度的影响,并拟合得到了掺GO再生混凝土的抗压强度与再生粗骨料取代率之间的关系表达式。结果表明:随着GO掺量的增加,试件的抗压强度呈先增大后减小的趋势,且当GO的掺量为0.063%时,试件的抗压强度达到最高;随着再生粗骨料取代率的增加,试件的抗压强度降低;ExpDec3指数函数可较为准确地表达掺GO再生混凝土的抗压强度与再生粗骨料取代率之间的关系。

电解锰渣-赤泥-粉煤灰路面砖的力学性能及浸出毒性研究

针对大宗工业固废回收利用难的问题,实现多种固废减量化、无害化、资源化的目标,通过利用取自中国西南地区企业的石膏类、碱性及硅铝质三类典型大宗固废中的电解锰渣、赤泥、粉煤灰协同处理的无害化渣制备环保型透水混凝土路面砖(permeable concrete paving bricks,PCB),研究了水洗、掺渣量对所制备PCB的力学性能与浸出毒性的影响,并通过X射线衍射(XRD)和扫描电子显微镜(SEM)对最佳性能PCB的物相组成与微观形貌结构进行分析.结果表明:①随着无害化渣与水洗无害化渣掺入量的提升,路面砖的劈裂抗拉强度、线性破坏荷载发生明显变化,总体呈下降趋势.当无害化渣掺入量为6%、水洗无害化渣掺入量为14%时,经28 d养护,所制备砖体的劈裂抗拉强度分别为4.09和3.46 MPa,达到了《透水路面砖和透水路面板》(GB/T 25993-2010)中规定的f_(ts)4.0与f_(ts)3.0等级.②路面砖的重金属与NH_(4)^(+)-N的浸出毒性均低于《水泥窑协同处置固体废物技术规范》(GB 30760-2014)的要求.路面砖的主要物相中方解石、石英与钙矾石是主要支撑性物质.研究显示,电解锰渣、赤泥、粉煤灰协同处理的无害化渣可替代部分原材料制备透水混凝土路面砖,满足力学性能与浸出毒性相关标准,能有效促进固体废弃物的减量化与资源化,建议进一步开展砖体在实际应用场景中的环境风险试验,以期为电解锰渣、赤泥、粉煤灰的综合利用技术发展提供更明确的支撑.

砖砂的掺量对干混砂浆性能的影响

文中分析了废弃红砖再生细骨料对干混砂浆性能的影响。结果表明,废弃红砖可作为粒状砂浆集料,优化混凝土密实性能。砖砂在骨料中占比30%时的抗压强度符合标准要求,通过调整外加剂等方式,可控制干混砂浆的稠度损失,该结论可为红砖废料制备混凝土再生粗骨料的应用提供依据。

红砖地坪材料在习酒高温制曲生产中的应用研究

传统高温制曲发酵仓内地坪材料为三合土,所需原材料不易寻找,需要较大的材料堆放和制备场地,施工工艺复杂,从原材料制作到铺筑需要8道工序,存在施工周期长、养护周期长、使用寿命短、易破损、修复难度大且耗时长等问题,不利于高温制曲生产。本研究创新性的更换红砖地坪,发现可以解决以上存在的问题,同时红砖地坪保温效果较好,能有效的促进高温制曲在后发酵期的生香作用。

红砖古厝元素在鞋靴设计中的应用

本文以闽南红砖古厝的装饰纹样为切入点,系统阐述了闽南红砖古厝的建筑特色、艺术价值和红砖装饰纹样样式;着重分析红砖四瓣柿蒂纹装饰纹样,对四瓣柿蒂纹和相关装饰元素进行外观特征提取和纹样的解构,让红砖古厝元素的图案与色彩通过现代设计的重组更好地与鞋靴设计结合。在现代鞋靴设计中融入红砖古厝元素,既能提高鞋靴设计的艺术风格,增加鞋靴产品的市场竞争力,又能更好地传播与深化人们对闽南红砖古厝这一非物质文化遗产的认知。

城市污泥用于生产环保红砖的研究

评估了污水处理厂污泥用于生产红砖的可行性。处理污水的过程会产生大量污泥,主要是有机污泥,这些污泥通常被填埋在垃圾填埋场。通过微观结构和物理力学分析,评估了两种不同类型的污泥(从0~10%代替黏土)作为红砖生产的原材料使用。结果表明,污泥的加入降低了砖的表观密度,增加了砖的风化敏感性,这是由于在烧制过程中产生了更高的孔隙率。在生产红砖的黏土混合物中加入6%的污泥是一种可行的、可持续的、低环境影响的回收解决方案。

“海丝”视野下福清传统红砖文化基因类型研究

福清传统红砖蕴含着福建海丝文化基因的艺术风貌和秩序特征,包含着福清人的文化认同、场所认同和价值观念。文章深入解析“海丝”视野下的福清文化基因遗传密码,通过结构、色彩、图纹、肌理等基因因子的识别和类型组构,总结归纳福清传统红砖文化基因形态类型特征。展现了福建海丝文化的理性之美、大度之美和共情之美,以期保护、传承地方文化多样性,为建设宜居宜业和美乡村提供新艺术设计思路。

电解锰渣-赤泥路面砖中锰的浸出行为研究及长期释放预测

电解锰渣和赤泥是电解锰和氧化铝生产过程中的副产物,由于缺乏有效的管理手段,导致其存量持续积累,造成了严重的环境影响和资源浪费,因此有必要对其进行资源化利用,以减小环境影响并促进冶炼锰、铝行业的绿色可持续发展.该研究使用无害化渣和水洗无害化渣,结合水泥、石料和河砂等原料,按一定配比制备得到透水混凝土路面砖(permeable concrete paving bricks,PCB)和水洗透水混凝土路面砖(washed permeable concrete paving bricks,WPCB),为评估两种路面砖在柳州市长期使用过程中存在的潜在环境风险,采用欧盟标准化组织制定的NEN 7375方法研究特征污染物Mn^(2+)的浸出行为,通过多种动力学方程拟合并预测Mn^(2+)的浸出行为,并借助IWEM模型对路面砖的拟利用路面区域进行评估.结果表明:①在相同的配比条件下,WPCB中Mn^(2+)的累积释放量较PCB更低;在不同的配比条件下,Mn^(2+)的累积释放量随渣掺量的增加呈现先降低后升高的趋势.②除水洗无害化渣和水泥掺量分别为8%和25%的WPCB-2在全浸出阶段中Mn^(2+)的浸出行为受扩散控制影响外,其余样品均受表面冲刷影响.③对于选取的4种动力学方程,Elovich方程更适合描述Mn^(2+)的浸出行为,且PCB和WPCB于10年和20年内Mn^(2+)的预计释放量分别在1.51~13.78和1.71~16.54μg/kg之间.④IWEM模型的模拟结果显示,路面砖符合环境安全性要求.研究显示,两种无害化渣所制得的路面砖在实际应用场景中均无潜在的环境风险,可进一步扩展其资源化利用场景.

掺红砖微粉地聚物再生混凝土耐久性能

为研究红砖微粉掺量对地聚物混凝土耐久性能的影响,将红砖微粉作为胶凝材料分别取代粉煤灰与矿渣,取代率分别用F和S表示,设计了9种组合方式,通过碳化试验、氯离子渗透试验及冻融循环试验对红砖微粉掺量与混凝土抗碳化性能、抗氯离子渗透性能、抗冻性能之间的关系进行了研究。结果表明:当F值为0~20%时,对混凝土的耐久性能有益;当F=15%时,混凝土抗碳化性能、抗冻性能达到峰值;混凝土抗氯离子渗透性能随着F值的增大逐渐增加。当S值为0~20%时,混凝土抗冻性能随着S值的增大逐渐降低;当S=5%时,混凝土抗碳化性能、抗氯离子渗透性能达到峰值。

基于闽南红砖建筑装饰艺术的文创产品设计研究

目的 以研发“世遗泉州”闽南红砖文创产品为目的,进行闽南传统文化的创新设计研究,以期能为闽南传统文化创新运用和活化传承提供一定的实践参考。方法 挖掘“世遗泉州”独特地域文化,解读与梳理当地闽南红砖建筑装饰艺术的文化价值,并提炼当中的文化符号;结合“日用即道”的设计理念提出研发闽南红砖文创产品要遵循地域性、实用性、情感性和可持续性的设计原则,以创新手段将闽南红砖建筑艺术与现代产品相融合,进行闽南红砖茶文化产品实践设计。结论 将闽南地区独有的红砖建筑装饰艺术与百姓日常生活相结合,形成具有独特属性和文化定位的文创产品,在为当地带来经济效益和社会效益同时,还有助于传承与保护闽南传统文化资源。

预湿与附加用水组合处理方式下高红砖含量再生粗骨料替代率对C20混凝土性能影响研究

研究了预湿与附加用水组合处理方式下,高红砖含量再生粗骨料替代率对C20再生粗骨料混凝土流动性能与抗压强度以及界面微观结构的影响。结果表明,在预湿与附加用水组合处理方式下,当高红砖含量再生骨料替代率小于50%时,混凝土流动性能与抗压强度受再生骨料替代率的影响较小;当再生骨料替代率超过50%后,即便采用预湿与附加用水组合处理方式,混凝土减水剂用量仍显著增大,混凝土流动性能受到明显影响,同时混凝土7、28 d抗压强度均显著降低;高红砖含量再生粗骨料对混凝土骨料与浆体界面结构的弱化作用,是其替代率过大时,混凝土抗压强度降低的主要原因。

闽南传统红砖民居聚落空间营建中的道家美学--以南安蔡氏红砖聚落为例

闽南地处福建东南沿海,其民居建筑营建极具闽南地域特色和历史渊源,有很高的研究价值。文章聚焦于闽南传统保护村落“南安蔡氏古民居建筑群”,通过田野考察和文献分析等方法,从建造目标、区位环境、构造体系和装饰特色四个方面展开,探究了“天人合一”“无中生有”“虚实相生”“师法自然”等道家美学思想在蔡氏红砖聚落空间营造中的运用,希望为今后闽南民居建筑的研究与保护提供参考。

“小红砖”在建筑工程领域应用现状与发展建议

以“小红砖”为典型代表的烧结砖制品在建筑工程领域的应用历史悠久,是具有优良性能的传统建筑材料之一,现代烧结砖制品已充分摆脱过去毁田制砖、资源能源消耗大的面貌,取而代之的是工艺技术先进、具有环保利废特征的新型“小红砖”。本文通过梳理“禁实限粘”政策实施过程,立足行业实际,分析了烧结砖制品在建筑工程领域推广应用的现状及难点,围绕其技术发展特点,提出了加强烧结砖制品行业应用的思考建议,旨在为促进建筑品质提升和好房子建设提供材料支撑。