不锈钢渣和矿渣制备胶凝材料的试验研究

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.     

Hydraulic binders of Fluorgypsum–Portland cement and blast furnace slag,stability and mechanical properties

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.     

Use of diatomite as partial replacement for Portland cement in cement mortars

The aim of the present study is to investigate the use of diatomite as a partial replacement for cement in the production of cement mortar. Diatomite was used at 0%, 5%, 10% and 15% replacement by weight for cement while sand and water quantities were kept constant. Compressive and flexural strength, freeze–thaw resistance, sulfate resistance, water absorption and dry unit weight of the mortars were determined. The compressive and flexural strength decreased with increasing diatomite content for all curing periods. However the compressive strength of the cement mortar which was produced with 5% diatomite content complied with the minimum specified value of given in the standards. Diatomite replacement generally increased the compressive strength of the cement mortar after 25 freezing and thawing cycles. Water absorption of the mortars decreased with the increase of diatomite content except the mortar containing of 15% diatomite. Dry unit weight of the cement mortar was lower than the control mortar because of high porosity of diatomite. The expansion of the cement mortar bars immersed in 5% sodium sulfate solution decreased with increasing diatomite content and generally the sulfate resistance of the mortars was higher than that of the control mortar.     

Waste gypsum–blast furnace slag cement in mortars with granulated slag and silica sand as aggregates

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.     

Lightweight concretes of activated metakaolin-fly ash binders,with blast furnace slag aggregates

This work investigated geopolymeric lightweight concretes based on binders composed of metakaolin with 0% and 25% fly ash, activated with 15.2% of Na₂O using sodium silicate of modulus SiO₂/Na₂O = 1.2. Concretes of densities of 1200, 900 and 600 kg/m³ were obtained by aeration by adding aluminium powder, in some formulations lightweight aggregate of blast furnace slag was added at a ratio binder:aggregate 1:1; curing was carried out at 20 and 75 °C. The compressive and flexural strength development was monitored for up to 180 days. The strength diminished with the reduction of the density and high temperature curing accelerated strength development. The use of the slag had a positive effect on strength for 1200 kg/m³ concretes; reducing the amount of binder used. The thermal conductivity diminished from 1.65 to 0.47 W/mK for densities from 1800 to 600 kg/m³. The microstructures revealed dense cementitious matrices conformed of reaction products and unreacted metakaolin and fly ash. Energy dispersive spectroscopy and X-ray diffraction showed the formation of amorphous silicoaluminate reaction products.     

矿渣微粉和激发剂对水泥性能的影响

将低混合材掺量的P.O 42.5R级水泥作为母水泥,掺入S75矿渣微粉制得混合水泥,系统研究了矿粉掺量及SJ-1激发剂对混合水泥性能的影响。结果表明,无论有无激发剂,随着矿粉掺量增大,混合水泥标准稠度需水量及凝结时间均有所增加,但变化不大;无激发剂情况下,在试验掺量范围内,与母水泥相比,混合水泥的后期强度变化不大,但早期强度却有所降低;掺入激发剂后,混合水泥的后期强度高于母水泥的,早期强度与母水泥相当,但明显大于对应的不掺激发剂的混合水泥。     

Properties of cement mortars containing clinoptilolite as a supplementary cementitious material

This paper presents a study of the properties and behavior of cement mortar with clinoptilolite which is one of the most common zeolite minerals found in nature. Six mortar mixtures were prepared by replacing the Portland cement with 0%, 5%, 10%, 15%, 20% and 30% clinoptilolite by weight. Test results showed that water demand, soundness and setting times of the cement pastes increased with the increase of clinoptilolite content. Compressive and flexural strength of the mortars containing clinoptilolite were higher than the control mixture. Dry unit weight of the mortars with clinoptilolite was lower than the control mortar. Clinoptilolite replacement decreased water absorption and porosity of the mortars. The control mortar showed less durability to carbonation compared to the mortars made with clinoptilolite at the end of carbonation tests. Freeze–thaw resistance of the mortars containing 5% clinoptilolite was higher than control mortar. The effect of clinoptilolite incorporation on high-temperature resistance seemed to be dependent on amount of clinoptilolite, temperature level, and the cooling method.     

新型高炉矿渣基尾矿胶结材料的制备试验研究

主要探讨以炼铁高炉矿渣为原料,通过添加活化剂,制备新型尾矿胶结材料,用于矿山胶结充填。针对某炼铁高炉矿渣,通过试验筛选了合适的激发剂和早强剂,确定了对应的最佳添加量,提出了新型高炉矿渣基尾矿胶结材料的优化配合比,为高炉矿渣高附加值开发利用开辟了一条新途径。     

粉煤灰、矿渣复合硅酸盐水泥的研制

本文对粉煤灰和矿渣作混合材生产复合水泥采用不同的粉磨工艺进行对比,采用矿渣预粉磨工艺使复合水泥的早期强度明显提高,混合材总掺量达40％时,不加任何外加剂仍然能生产425R复合水泥。     

The use of ground blast furnace slag,chrome slag and corn stem ash mixture as a coating against corrosion

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.     

利用矿渣和脱硫灰制备新型胶凝材料的试验研究

以矿渣和脱硫灰为主要原料,并掺人少量石膏,在外加剂的作用下,可制备出一种具有较高活性的胶凝材料.研究了石膏、激发剂和脱硫灰掺量对复合胶凝胶凝材料强度的影响.并对较优配合比的胶凝材料的水化产物进行了XRD与SEM分析.结果表明:当矿渣、脱硫灰、二水石膏和激发剂的质量比为85:5:6:4时可制备出满足现行国家标准的胶凝材料...     

Characterization of ladle furnace basic slag for use as a construction material

The use of ladle furnace basic slag (LFS) as a cementitious material in industrial applications requires an in-depth knowledge of its characteristics. This paper presents the data characterizations of several kinds of LFS, setting out referential values for their use in construction and civil engineering applications that refer to chemical, mineralogical and microstructural data as well as to thermal and infrared analytical results. The aim is to provide a detailed overview of this material for anyone with an interest in gaining further knowledge of its specific properties for application as a construction material.     

Properties of self-compacting concretes made with binary,ternary, and quaternary cementitious blends of fly ash,blast furnace slag,and silica fume

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.     

复合激发剂在矿渣-钢渣-粉煤灰三掺混凝土中的应用研究

采用自制的高效复合激发剂,研究了其对矿渣-钢渣-粉煤灰三掺混凝土工作性能和力学性能的影响。结果表明:复合激发剂的使用,对新拌混凝土的工作性能没有不利影响;复合激发剂对设计等级为C30混凝土抗压强度提高的效果明显,而对C50混凝土的作用效果则有所减弱,其原因在于单位体积混凝土中高水泥含量时,水泥对钢渣的水化在早期具有一定的抑制作用。     

Durability of concrete incorporating non-ground blast furnace slag and bottom ash as fine aggregate

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.     

The effect of slaked lime,anhydrous gypsum and limestone powder on properties of blast furnace slag cement mortar and concrete

Basic properties of blast furnace slag cement mortar and concrete are investigated by adding inorganic activators. The result of this research concludes that slag cement mixed with suitable activator agents such as lime, gypsum and limestone powder could accelerate the compressive strength and tighten pore structure at early age. The addition of activator into mortar and concrete containing slag cement produces superior properties, reduced shrinkage and less carbonation compared to mortar and concrete containing slag cement without the addition of activator. Consequently, there are possibilities for manufacturing blast furnace slag cement, which could compensate the weak properties at early curing age. When compared with ordinary Portland cement, this cement has superior characteristics for long curing age.     

高炉水淬渣替代河砂制建筑砂浆的应用研究

通过对安钢高炉水淬渣的各项物理性能的测试分析，研究用其替代河砂制建筑砂浆的可行性，试验表明，高炉水淬渣完全可以替代河砂用于配制M10及其以下的建筑砂浆。     

Observations on the use of ground waste clay brick as a cement replacement material

The project is funded by the European Copernicus programme and involves the recycling of waste clay brick and tile material for the partial replacement of cement in mortar and concrete. The paper reports on the preliminary investigation of the effect on the strength development of concrete of partially replacing the cement with ground 'Fletton' brick and establishes that this brick does exhibit pozzolanic activity and does make a contribution to the strength development of concrete.     

Basic oxygen furnace slag as a treatment material for pathogens: Contribution of inactivation and attachment in virus attenuation

Basic oxygen furnace (BOF) slag media were studied as a potential treatment material in on-site sanitation systems. Batch and column studies were conducted to evaluate attenuation of the bacteriophage PR772 and 0.190 μm diameter microspheres by BOF media, and to delineate the relative contributions of two principle processes of virus attenuation: inactivation and attachment. In the batch studies, conducted at 4°C, substantial inactivation of PR772 did not occur in the pH 7.6 and 9.5 suspensions. At pH 11.4, bimodal inactivation of PR772 was observed, at an initial rate of 2.1 log C/C₀ day⁻¹ for the first two days, followed by a much slower rate of 0.124 log C/C₀ day⁻¹ over the following 10 days. Two column studies were conducted at 4°C at a flow rate of 1 pore volume day⁻¹ using two slag sources (Stelco, Ontario; Tubarão, Brazil) combined with sand and pea gravel. In both column experiments, the effluent microsphere concentration approached input concentrations over time (reductions of 0.1-0.2 log C/C₀), suggesting attachment processes for microspheres were negligible. Removal of PR772 virus was more pronounced both during the early stages of the experiments, but also after longer transport times (0.5-1.0 log C/C₀). PR772 reduction appeared to be primarily as a result of virus inactivation in response to the elevated pH conditions generated by the BOF mixture (10.6-11.4). On-site sanitation systems using BOF media should be designed to maintain sufficient contact time between the BOF media and the wastewater to allow sufficient residence time of pathogens at elevated pH conditions.     

硅钙渣脱碱处理及作水泥混合材的研究

采用正交试验法对硅钙渣进行脱碱处理,对脱碱前后的硅钙渣水泥性能进行了研究。通过调整温度、保温时间、石灰乳掺量和水洗次数,得出最佳脱碱组合为:石灰乳掺量10%,温度85℃,保温时间3 h,水洗2次,处理后碱含量为0.83%;强度试验结果表明,水化早期未脱碱硅钙渣水泥抗压强度要高于脱碱硅钙渣水泥,但随着龄期逐渐增长,脱碱硅钙渣水泥优势逐渐显现,掺量越大优势越明显;微观形貌分析表明,未脱碱硅钙渣水泥水化早期生成大量C-S-H凝胶,水化产物较脱碱硅钙渣水泥更致密,水化28d时两者水化产物的致密性相当。