共查询到20条相似文献,搜索用时 0 毫秒
1.
Mehmet Gesoğlu Erhan Güneyisi Erdoğan Özbay 《Construction and Building Materials》2009,23(5):1847-1854
Self-compacting concretes (SCCs) have brought a promising insight into the concrete industry to provide environmental impact and cost reduction. However, the use of ternary and especially quaternary cementitious blends of mineral admixtures have not found sufficient applications in the production of SCCs. For this purpose, an experimental study was conducted to investigate properties of SCCs with mineral admixtures. Moreover, durability based multi-objective optimization of the mixtures were performed to achieve an optimal concrete mixture proportioning. A total of 22 concrete mixtures were designed having a constant water/binder ratio of 0.44 and a total binder content of 450 kg/m3. The control mixture included only a Portland cement (PC) as the binder while the remaining mixtures incorporated binary, ternary, and quaternary cementitious blends of PC, fly ash (FA), ground granulated blast furnace slag (S), and silica fume (SF). Fresh properties of the SCCs were tested for slump flow diameter, slump flow time, L-box height ratio, and V-funnel flow time. Furthermore, the hardened properties of the concretes were tested for sorptivity, water permeability, chloride permeability, electrical resistivity, drying shrinkage, compressive strength, and ultrasonic pulse velocity. The results indicated that when the durability properties of the concretes were taken into account, the ternary use of S and SF provided the best performance. 相似文献
2.
3.
Waste gypsum–blast furnace slag cement in mortars with granulated slag and silica sand as aggregates
J.I. Escalante-García R.X. Magallanes-Rivera A. Gorokhovsky 《Construction and Building Materials》2009,23(8):2851-2855
The performance and water resistance of binders 30–50% blast furnace slag and hemihydrate from waste gypsum were investigated. Mortars of various aggregate:binder ratios were prepared with granulated BFS and silica sand. The cements with 50% slag were the best in terms of strength; higher aggregate loads reduced the strength. The solidification of mortars by the formation of an initial gypsum framework was indicated by the very fast setting, low 1 day strength and high non-evaporable water. Further strength development was due to the slag reactions. The microstructures of polished samples were dense and conformed by gypsum crystals surrounded by C–S–H. The use of BFS sand was more efficient, in terms of strength, than silica sand; this was due to the participation of the slag aggregate in the hydration reactions, improving the bonding in the interfacial zone. The lower density of the former makes them potentially more insulating efficient. 相似文献
4.
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. 相似文献
5.
《Construction and Building Materials》2010,24(5):631-639
The effect of various additives (Ca(OH)2, K2SO4, Na2SO4, Al2(SO4)3) was evaluated on the hydraulic character and stability of pastes of 50–75% Fluorgypsum, 15–30% Portland cement and 10–20% Blast furnace slag. Characterization included length changes, compressive strength, SEM, DTA and XRD. The combination of Na2SO4 and Al2(SO4)3 favored early strength but caused detrimental expansion and strength losses after 90 days; whereas the use of only K2SO4 was favorable for strength and dimensional stability. The type of additive had a more important effect on stability and strength than the amounts of cement and slag. XRD indicated the presence of anhydrite, gypsum, ettringite, CaCO3 and an unidentified phase, the interaction of these is proposed to explain the behavior of the cements investigated. SEM showed that cement and slag reacted forming C–S–H that enhanced the hydraulic character by engulfing the gypsum crystals. 相似文献
6.
7.
粒化高炉矿渣代砂混凝土力学性能试验 总被引:1,自引:0,他引:1
研究了粒化高炉矿渣作为混凝土细骨料时的基本特性及其不同代砂率混凝土的物理力学性能。结果表明:粒化高炉矿渣与天然砂在化学成分及物理性能方面存在一定差异。在相同水胶比的条件下,相比于普通混凝土,粒化高炉矿渣代砂混凝土的流动性较差且含气量较高;与普通混凝土相比,粒化高炉矿渣代砂混凝土早期抗压强度较低但其后期强度增长较快,且粒化高炉矿渣代砂率越高后期强度增长越快;粒化高炉矿渣代砂混凝土劈裂抗拉强度和普通混凝土较为接近;粒化高炉矿渣代砂混凝土28 d弹性模量和普通混凝土较为接近且随混凝土强度等级的提高而增加。 相似文献
8.
9.
The ground blast furnace slag (GBFC), chrome slag (CS) and corn stem ash (CSA), produced following a number of processes, were mixed with pitch in different proportions in order to increase adherence. Iron plates were then coated with this mixture. The coated and uncoated plates were left to corrode in a NaCl solution (35 g/L NaCl). The potential differences of the specimens were measured after they were kept in the solution for a month by electrodes. The potential difference for the uncoated iron plates (iron plates without GBFC, CS and CSA) was approximately 0.501 V. For those coated with pitch, this value was 0.363 V. On the other hand, the potential difference of the coated iron electrodes was determined to be 0 V revealing the absence of corrosion after the NaCl solution treatment and the suitability for the use of the ground blast furnace slag, chrome slag and corn stem ash as coating materials. 相似文献
10.
The paper presents investigation of how the usage of bottom ash (BA), granulated blast furnace slag (GBFS), and combination of both of these materials as fine aggregate in concrete affects the concrete durability. To assess durability characteristics of concrete, durability tests were conducted and the results were evaluated comparing with reference concrete. Three series concrete were produced. GBFS, BA and GBFS+BA are replaced the 3–7 mm-sized aggregate. Five test groups were constituted with the replacement percentages as 10%, 20%, 30%, 40% and 50% in each series. These by-products were used as non-ground form in the concrete. Durability properties of the concretes were compared in order to study the possible advantages of different replacement ratios. According to results, GBFS and BA affects some durability properties of concrete positively in case of it is used as fine aggregate. Resistance to high temperature and surface abrasion are positively affected properties. Capillarity, drying-wetting and freezing-thawing resistance of the concrete can be accepted to some extent. Properties of by-products and its replacement ratio are controlling the influence level and direction. Comparison of the SEM images and test results show that chemical and physical properties of GBFS and BA are the main factors affecting the concrete durability. It is concluded that it is possible to produce durable concrete by using GBFS and BA as fine aggregate. 相似文献
11.
12.
13.
The paper presents the results of a laboratory study, aimed at verifying the possibility to use two particular typologies of electric arc furnace (EAF) steel slags, in substitution of the natural aggregates, in the composition of wearing course asphalt concrete for flexible pavements. The experimental research has been articulated in a preliminary study of the chemical, leaching, physical, and mechanical properties of the EAF steel slag, and in the following mix design and performance characterisation of the bituminous conglomerates, through gyratory compaction tests, permanent deformations tests, Stiffness Modulus tests at various temperatures, fatigue tests and indirect tensile strength tests. All the mixtures with EAF slag have satisfied the requisites for acceptance in the road sector technical standards, thus resulting as suitable for use in the construction of road infrastructures, moreover presenting higher mechanical characteristics than those of the corresponding asphalts with full natural aggregate. 相似文献
14.
15.
以贵州省六盘水市水钢高炉重矿渣为试验原料,分析了原料的化学成分、物相组成,并对高炉重矿渣集料的物化力学性能进行了试验研究。以100%高炉重矿渣集料为骨料可获得了C20高炉重矿渣混凝土和M10砂浆,其各项物理力学性能均符合规范要求,这为水钢重矿渣的开发利用提供了理论依据。 相似文献
16.
以不锈钢渣和矿渣为主要原料,配加脱硫石膏、粉煤灰、矿物激发剂制备胶凝材料,通过试验确定了原料的最佳质量配比:33%不锈钢渣、35%矿渣、5%脱硫石膏、5%粉煤灰、22%矿物激发剂,利用该配比制备的胶凝材料达到32.5级普通硅酸盐水泥的标准要求.同时,采用XRD分析了胶凝材料的矿相组成,采用扫描电镜对胶凝材料不同龄期水化产物的显微结构进行了分析. 相似文献
17.
18.
从粒化高炉矿渣粉的基本概念出发,通过对照高价标准,对粒化高炉矿渣粉在混凝土中的作用原理进行了分析,提出了在实际混凝土中应用高炉矿渣粉应该注意的几个问题,以指导实践。 相似文献
19.