多孔轻集料植被混凝土试验研究

对水泥、粉煤灰等实验原材料进行了介绍,分析了减水剂、粘合剂和粉煤灰对多孔轻集料植被混凝土性能的影响,并通过试验得出掺加减水剂、粘合剂等可以配制碱度低、合适孔隙率及抗压强度2 MPa~3 MPa以上的多孔轻集料植被混凝土的结论。     

人造轻集料混凝土试验研究

本文阐述了一种采用人造轻集料——瓷渣球形陶粒为粗集料,配制出强度等级LC30~LC60,密度1600~1900kg/m^3的结构用轻集料混凝土,对不同配合比的强度、密度、坍落度进行试验,并与普通碎石混凝土进行了对比。探明了在相应条件下,陶粒混凝土密度降低(约25%),强度降低(约20%);球形陶粒混凝土,流动性好(但1h、1.5h坍度损失较大);相同密度等级时,陶粒混凝土抗压强度,随水泥的含量、减水剂的用量增加而增加。     

高强轻集料混凝土的性能试验研究

本文以碎石型页岩陶粒为骨料,配制LC30-LC50等级的混凝土,测试混凝土的力学性能和耐久性,并分析其原因。     

免振捣自流平高性能轻集料混凝土和高性能轻集料混凝土的研究

本文介绍了国内高性能轻集料的生产状况，指出应加强轻集料混凝土的耐久性研究，应拓宽高性能轻集料混凝土应用的领域；通过试验指出配制免振捣自密实混凝土的可行性，指出开发新掺合料的几个途径。     

轻集料混凝土砖的研制及应用

利用当地电厂粉煤灰和煤渣为主要原料,适当加入少量水泥和外加剂生产粉煤灰混凝土砖和多孔砖,已通过市级鉴定和应用于学校、厂房等建筑物。     

轻集料混凝土的界面结构研究

通过利用SEM对轻集料和水泥石的界面结构的研究,揭示了轻集料和水泥石的“嵌套”界面结构是轻集料混凝土早期强度高的根本原因,并阐述了轻集料对水泥石的“自养护”作用规律。     

轻集料混凝土力学特性及其对集料的要求

分析整理了二十余年的试验数据,设计施工经验的基础,通过对比的方法,把高强轻集料混凝土的主要力学性能进行了整理,并提出高强轻集料混凝土对集料的要求,目的是促进高强轻集料混凝土在高层、大跨结构上的推广应用。     

有机合成纤维增强高性能轻集料混凝土的研究

研究了三种有机合成纤维对高性能轻集料混凝土性能的影响。结果表明,掺入一定量的有机合成纤维,可以有效抑制轻集料的上浮,防止分层离析现象的发生。掺入高强高弹模聚乙烯纤维,能明显改善高性能轻集料混凝土的各项力学性能。有机合成纤维的掺入改变了高性能轻集料混凝土的破坏形式,降低了脆性,弯曲韧度系数最高可提高14倍。     

Durability of lightweight concretes with lightweight fly ash aggregates

This paper presents the effects of aggregate properties such as strength, porosity, water absorption, bulk density and specific gravity on the strength and durability of lightweight fly ash aggregate concrete (LWAC). The influence of properties of four aggregates (sintered lightweight fly ash aggregates, cold-bonded lightweight fly ash aggregate and normalweight aggregate) on mechanical and durability properties of concrete is discussed. Experimental results revealed that durable high-strength air-entrained lightweight concretes could be produced using sintered or cold-bonded lightweight fly ash aggregates, having comparable performance with the normalweight concretes. The use of lightweight aggregates (LWA) instead of normalweight aggregates in concrete production decreased the strength and stiffness due to the higher porosity and lower strength of the aggregate included in the concrete. However, permeability of sintered fly ash aggregate lightweight concretes was comparable and slightly lower than normalweight concrete whereas permeability of cold-bonded fly ash lightweight concrete was greater than the others. All concretes had a durability factor greater than 85, which met the requirements by showing quite perfect resistance to freeze–thaw.     

对轻集料粒型的思考

从我国对轻集料的研究发展以来,除天然轻集料（例如浮石、火山渣等）和工业废料轻集料（例如自燃煤矸石等）为碎石型轻集料外,大多数人造轻集料（例如黏土陶粒、页岩陶粒和粉煤灰陶粒）均为圆球型轻集料。虽然《轻集料混凝土技术规程》 ＪＧＪ１５－９０把轻粗集料分为圆球型、普通型和碎石型,但其主要是按生产工艺进行的划分,而这里不考虑生产工艺,只按颗粒形状分为碎石型和圆球型。而国外大多采用碎石型轻集料。这固然和我国轻集料的生产工艺有关,但两种粒型哪种对轻集料混凝土的性能特别是商品混凝土的泵送性能更为有利,目前我国…     

发泡剂对赤泥轻质免烧砖性能的影响

以赤泥、粉煤灰、水泥为主要原料,掺加一定量的激发剂和发泡剂,制备了赤泥轻质免烧砖。研究了发泡剂掺量对赤泥轻质免烧砖性能的影响。利用扫描电子显微镜对赤泥轻质免烧砖破坏断口进行了微观形貌分析。结果表明,当发泡剂掺量为10ml时,制得的试样性能较好,其密度、抗折强度、抗压强度分别为423kg／m3．049MPa和1.87MPa。     

集料干涉对轻质混凝土匀质性的影响

在构建"集料干涉假说"的理论基础下,作者用动量守恒定理建立了集料干涉的数学模型,揭示了集料干涉的本质机理,提出了改善轻质混凝土匀质性的技术途径;并在此基础上分别研究了集料的相对体积比例、集料的颗粒级配对轻质混凝土匀质性的影响规律,最后提出了集料之间发生明显干涉的条件.     

Fly ash lightweight aggregates in high performance concrete

Lightweight aggregates have been manufactured by sintering fly ash and crushing the product into suitable sizes. These aggregates possess unique characteristics that make them suitable for high strength and high performance concrete. Concrete produced using these aggregates is around 22% lighter and at the same time 20% stronger than normal weight aggregate concrete. Drying shrinkage is around 33% less than that of normal weight concrete. Moreover, the aggregates possess high durability characteristics required in high performance structures. The importance of the new aggregates lies mostly in the fact that superior qualities are achieved without having to increase the cement content. Thus it is possible to reduce the amount of cement by as much as 20% without affecting the required strength. Weight reduction may reduce precast concrete transportation costs as well as provide slender and spacious construction. Utilising fly ash to produce quality aggregates should yield significant environmental benefits.     

新型圆形陈化库及应用

介绍了新开发的圆形陈化库,主要由库体、布料机构、卸料机构及料位检测器等部分组成,彻底解决了传统陈化库物料水分易蒸发,布料不均匀,无法做到先进先出,扬尘不易收集处理等问题,可充分保证砖瓦生产企业的原料陈化效果。     

关于一种新型蒸压硅酸盐砖——石膏基蒸压磷渣硅酸盐砖探讨

对生产新型蒸压硅酸盐砖的主要原料磷渣和磷石膏作了介绍,对磷渣的水化反应机理、磷石膏的脱水转化产物和砖的强度及耐水性能的形成机理进行了探讨,对新型蒸压硅酸盐砖的科学研究和生产实例作了简要介绍,最后对其命名和定义的确定进行了讨论,认为新型蒸压硅酸盐砖宜称作"石膏基蒸压磷渣硅酸盐砖"。     

一种新型的折叠式擦窗机

近年来随着城市化进程的推进和科学技术的发展,高层楼面安装擦窗机的必要性已得到了普遍认可,而且擦窗机是外墙高空作业最安全、实用、高效的专用维护设备。由于建筑物的高度、外观、立面结构形式、楼顶空间尺寸都不相同,形成了擦窗机最大的特点就是非标准性。随着高楼结构形式越来越复杂化,常规擦窗机已经难以实现高层复杂楼面的幕墙清洗维护工作,笔者公司针对楼面空间狭小、墙高及设备上空有花架横梁等独特建筑形式和特殊环境,打破常规设计理念,克服现有技术中存在的不足,成功地研制了一种含机械传动、液压伸缩、PLC系统控制和安全保护装置的多功能新型折叠式擦窗机产品,为高层外墙清洗维护提供一种结构巧妙、外形美观、安全可靠的维护设备。     

Optimisation of using lightweight aggregates in mitigating autogenous deformation of concrete

Experiments were conducted to determine the effects of using dispersed saturated lightweight aggregates (LWAs) as water reservoirs in mitigating the autogenous deformation of high performance concrete and to establish the optimum solutions as a combination of a number of factors affecting the fracture and mechanical characteristics of concrete. For this purpose, in concretes prepared with a constant low water to cement ratio, normal aggregates were replaced by natural LWAs with size fractions of 2–4 mm or 4–8 mm at three different volume fractions such as 10%, 20% and 30% of the total aggregate volume of concrete. The results indicate that the inclusion of fine fraction of LWAs in concrete reduces the autogenous deformation significantly compared to that of the coarse fraction. It is also shown that concretes with fine fraction of LWAs have enhanced fracture and mechanical properties compared to those with coarse fraction of LWAs. Increasing the replacement ratio of LWAs mitigates autogenous deformation, while having an unfavourable effect on fracture and mechanical properties of concrete for both size replacements. A multi-objective simultaneous optimisation technique, in which the response surface method (RSM) is incorporated, is used to optimise the mitigation ratio of autogenous deformation and fracture parameters of high strength concretes in an effort to obtain a more ductile concrete with less autogenous deformation.     

Characteristics of self-consolidating concrete using two types of lightweight coarse aggregates

This paper presents the development of lightweight aggregate self-consolidating concrete (SCC) using two types of lightweight aggregates having different densities. Lightweight aggregate SCC properties have been evaluated in terms of flowability, segregation resistance and filling capacity of fresh concrete as per the standards of the Japanese Society of Civil Engineering (JSCE). The measurement of the mechanical properties of hardened lightweight aggregate SCC, including compressive strength, splitting tensile strength, elastic moduli and density, as well as its specific strength were also carried out. The characteristics of lightweight aggregate SCC at the fresh state showed that as the density of the lightweight coarse aggregate decreases, the flowability improves but the segregation resistance tends to decrease. The 28-days compressive strength of the lightweight SCC was found to be 32 MPa or higher. The relationship between the compressive strength and the splitting tensile strength was found to be similar to the expression presented by CEB-FIP, and the relationship between the compressive strength and the elastic moduli was found to be similar to the expression suggested by ACI 318-05 which takes into consideration the density of concrete. The density of the lightweight aggregate SCC decreased by up to 14% compared to that of the control SCC, and the specific strength decreased by up to 20%.