全固废无水泥钢渣重载路面混凝土的研究及工程应用.pdf

全固废无水泥钢渣重载路面混凝土的研究及工程应用 周 佳 倪 文 北京科技大学土木与环境工程学院, 北京 100083 牛福生 河北理工大学, 唐山 063009 摘要 在完全不使用硅酸盐水泥的条件下, 系统研究了以碱溶液激发钢渣、矿渣细粉、粉煤灰等工业废渣粉制备胶凝 材料, 钢渣为粗细骨料全部代替传统天然砂石, 配置路面混凝土。 配置出 28 d 抗压强度达44MPa, 抗折强度达8. 3 MPa 同时具有良好工作性能的钢渣路面混凝土。 进行重载路面工程试验的效果良好。 关键词 粉煤灰 路面混凝土 钢渣 矿渣 碱激发 1 前言 随着我国国民经济的不断提高 ,电力工业和炼钢 工业随之迅猛发展 ,使产生的工业废渣堆积如山, 因 此废渣减量化、资源化处理刻不容缓。而以天然砂石 和水泥为原料的传统混凝土由于水泥生产和砂石过 度开采造成的资源、能源与环境问题十分突出 。虽然 目前粉煤灰、 钢渣以及矿渣等具有水硬活性的工业废 渣已广泛用于建材和公路铁路建设 ,但也仅仅是作为 少部分代替水泥的填料来制备混凝土, 未能全部取代 水泥和天然砂石 ,同时也不能成为大批消耗粉煤灰等 工业废渣的有效方法 [ 1～ 6] 。 如果能将生产原料全部采用工业废渣,它的意义 将不仅在于解决大量工业废渣所造成的固体废弃物 污染, 更是实现资源的循环利用; 同时由于使用废渣 而不是水泥,避免由于生产水泥而引发的能源耗费以 及二氧化碳排放的大气环境问题。本研究使用以钢 渣碎石和钢渣砂代替传统混凝土所使用的天然砂石 为混凝土骨料, 并以由粉煤灰等工业废渣制备胶凝材 料代替传统水泥 ,生产建筑路面混凝土 。 2 原材料 在钢渣混凝土的研制过程中 ,使用钢渣碎石 粗 骨料 ,钢渣细砂作为混凝土粗细骨料 ,钢渣磨细粉, 矿渣磨细粉,粉煤灰和不同浓度的碱溶液以及适量外 加剂配制的胶凝材料代替水泥 。 1 钢渣碎石骨料 取自北京某公司, 为钢渣慢 冷的结晶产物, 质硬, 多孔 。本次试验所用骨料粒径 为10～ 20 mm 的钢渣碎石。 2 钢渣砂 取自北京某公司, 总 体粒径 10 mm 。 钢渣砂细度模数为 4. 07。 3 矿渣磨细粉 来自北京某公司, 为符合国家 标准的磨细高炉水淬渣 , 密度 2. 97 g cm 3 , 勃氏比表 面积约为 400 m 2 kg 。其化学分析结果见表 1。 4 钢渣磨细粉 来自北京某公司钢渣磨细粉生 产线, 勃氏比表面积约 350 m 2 kg , 密度 3. 22 g cm3 。 经XRD检测分析, 主要矿物成分为 γ -C2S、β -C2S 、RO 相、方镁石 、镁蔷薇辉石等矿物, 其化学分析结果 见表 1。 从表 1 看 , 钢渣磨细粉中 CaO、SiO2、Fe2O3含 量较高,Al2O3含量低,仅为 1. 93; 此外其MgO 含量 也相对较高 ,以方镁石及镁蔷薇辉石等物相存在。将 钢渣磨细粉制成试饼 ,经蒸煮试验确定无 f-CaO 引起 的安定性不良问题。 5 粉煤灰 来自北京某热电厂二级粉煤灰, 勃 氏比表面积约为 200 m 2 kg 。其化学分析结果见表 1。 表 1 各原料主要化学成分 项目 SiO2Al2O3Fe2O3 MgOCaO 钢渣磨细粉16 . 061. 9315. 478. 2748. 01 矿渣磨细粉32 . 629. 924. 218. 8941. 53 粉煤灰50 . 6031. 347. 225. 35 6 外加剂 自制碱溶液。 7 缓凝剂 自制缓凝型减水剂 。 8 IS0- 9000 标准砂 符合 GB T17671 -1999 。 3 试验方法 由粉煤灰、钢渣磨细粉、矿渣磨细粉按 3∶ 3∶ 4 比 例混合而成的废渣粉与碱溶液配制而成混合物称为 胶凝材料。 各种原材料的配比见表 2。 本次试验所使用仪器设备 、 制备方法 、 测试方法、 完全符合 GB T177-1985 水泥胶砂强度检验方法 和 GB T50081-2002 普通混凝土力学性能试验方法 标准的要求。 63 环 境 工 程 2005年 10 月第 23卷第 5 期 表 2 净浆、胶砂、混凝土原料种类及配比 编 号 碱溶液质量百 分比浓度 材料配比及试块体积 骨料 BS GFGC B -1 B -2 B -3 15 20 23 胶凝粉总质量 g∶ 溶液体积 mL4∶ 1, 采用 30 mm30 mm50 mm 试块测试抗压强度 - - - - - - - - - M -1 M -2 M -3 15 20 23 胶凝粉总质量 g∶ 溶液体积 mL∶ ISO 标准砂 2 ∶ 1 ∶ 6, 采用40 mm40 mm160 mm 试块测试 抗压强度 - - - - - - C-1 C-2 C-3 15 20 23 胶凝粉g∶ 溶液体积 mL∶ 粗细骨料总质量 6 ∶ 25 ∶ 4 ,采用150 mm150 mm150 mm标准试 块测试各龄期抗压强度 - - - 注 “ -” 该项原料的添加量为0 ;“ ”加入该原料,“BS” IS O 标准细砂; “GF” 钢渣砂; “GC” 钢渣碎石 4 结果及讨论 根据表 2 所列试验配方制作 、测试的试块 28 d 强度结果绘图 1,从图中看出 , 随浓度的升高净浆、胶 砂、 混凝土试块的抗压强度明显升高。 图 1 浓度对净浆、胶砂、混凝土强度的影响 图2 28 d SEM 图 图 2 a 所示为浓度为 15的净浆试块的 28 d SEM 图, 对比图 2 b 浓度为 23 的净浆试块的 28 d SEM 图, 图2 a 胶凝材料周围有明显的孔洞存在, 图 2 b 的结构非常致密, 前者的结构明显比后者的疏 松,可以认为胶凝材料胶结效率在碱溶液浓度较高时 好于浓度较低时的胶结效率, 因此导致 B -1 的强度低 于B-3; 硬化混凝土中存在有内聚力 [ 1] , 如果假设浓度 提高时,净浆、 胶砂、混凝土试块抗压强度的提高是由 于内聚力的提高 ,因而可以认为浓度提高可以提高混 凝土内聚力,因而导致材料的强度提高 。 如果从硬化混凝土的过渡区分析 硬化混凝土的 结构是由 3 部分组成 硬化胶凝材料 ; 集料 ; 硬化胶凝 浆体和集料间的过渡区 ,以天然砂石和普通水泥组 成的硬化混凝土的结构中 ,其过渡区结构的强度低于 胶凝材料浆体和集料相, 所以使得此类混凝土在承受 比硬化胶凝材料和集料强度低得多的荷载的作用下 而破坏。因此可以通过改善集料和胶凝材料浆体之 间的粘结力即改善硬化混凝土中的过渡区强度提高 混凝土的强度。 钢渣属于活性骨料, 相比其它天然骨料具有更高 的反应活性 。与碱性溶液作用下的胶凝浆体之间的 粘结力更强 ,即过渡区强度也更强 。根据表 2 和图 1 所示实验结果分析 , 当溶液浓度 15、20时 , 本研 究的工业废渣净浆材料的强度明显高于同浓度混凝 土的强度, 即硬化的 C-1和 C-2 混凝土中过渡区的强 度较低 ,因此整个硬化混凝土的强度也较低 ; 随着浓 度上升为 23时, 净浆试块的抗压强度几乎等于混 凝土试块的抗压强度化的 C-3 混凝土中过渡区结构 的强度升高 ; 即过渡区强度在溶液浓度提高时其强度 也随之提高 ,因此整个混凝土的强度也随之提高。 5 工程应用 在生产线附近修建一条重载车路面 。根据前面 的试验结果设计了如表 3 所示的混凝土配方 。经过 标准测试, 该配方的 28 d 抗压强度达 44 MPa, 抗折强 度达 8. 3 MPa。施工 1 a 后的路面情况, 路段使用状 况良好,无开裂现象 。 表 3 路面混凝土配比各原料价格 项目 钢渣 骨料 钢渣 磨细粉 矿渣 磨细粉 粉煤 灰 缓凝 剂 水玻璃 溶液 水 用量 tm- 32 083. 31201601200. 325178 . 9 价格 元t- 125100200805002006 如果以表 3 中所示价格计算, 混凝土的价格为 117. 0 元 m 3 , 商 用 传 统 C40 混 凝 土 的 价 格 约 200 元 m 3 。 因此钢渣混凝土的优点不仅在于节能环 保,其经济效益更加突出 。 如图 3 所示 ,碱溶液 粉煤灰废渣混凝土的强 度随龄期增长而提高 ,早期强度较高, 超过 28 d 后强 度增长趋于平缓 。 图3 施工路面各龄期抗压强度 下转第 66页 64 环 境 工 程 2005年 10 月第 23卷第 5 期 0. 025为异常值, 予以剔除。对剩余 21个空白值进行 统计计算, 得 X0 0. 017, S 0. 0014, 检出限 L03S K 30. 001 4 0. 157 0. 027 mg L ,按 10 mL 吸收液 和30 L 采样体积的方法 方法 B 进行计算, L氨L0 V吸收液 V采 0. 027 10 300. 009 mg m 3 ,此值为国 标方法检出限的 3. 6。 5 2种方法测定低浓度氨样品的比较 现以国标方法A XA 与方法 B XB 同时对采集 的系列低浓度氨样品进行分析 ,结果见附表。 附表 对比不同方法测定系列低浓度氨样品的结果 n 6 mg m3 项目1点位2点位3点位4点位 XA 未检出未检出0. 3160 . 566 XB 0. 0340 . 1290. 3360 . 524 SB 0. 0070 . 0200. 0410 . 054 T1. 191 . 91 T0. 05 5 2. 5712 . 571 评价 接受 H0接受 H0 统计检验结果表明 对于 3 、4 点位的样品, 方 法B 与国标方法的测定结果无显著性差异; 在 1 、 2 点位的低浓度样品测定中 ,国标方法都未能检出, 而方法 B 皆检出 , 且精密性良好。以上检验充分证 明,方法 B 在 0. 25 mg m 3 的低浓度氨样品测定中有 明显的优越性, 其检出限完全适合有关质量标准, 是 对国标方法测定低浓度氨的改进和优化 。 参考文献 1 中华人民共和国国家标准 GB T14668 -93 空气质量 氨的测定. 纳 氏试剂比色法. 北京 中国标准出版社, 2001. 2 中华人民共和国国家标准 GB T18883 -2002 . 室内空气质量标准. 国家环保局、卫生部,2003. 3. 1. 3 中华人民共和国国家标准 GBZ1 -2002 . 工业企业设计卫生标准. 中华人民共和国卫生部. 2002. 6. 1. 4 国家环境保护总局. 水和废水监测分析方法 第 4 版 . 北京 中国 环境科学出版社,1997. 作者通讯处 张素荣 226300 江苏省通州市金沙镇翠园路 10 号 通州市环境监测站 2004- 10-18 收稿 上接第 64页 6 结论 1 碱溶液浓度及用量适当提高可以提高碱激发 即提高了粉煤灰废渣粉胶凝材料的强度 。 2 碱溶液较低时 , 碱溶液激发废渣粉胶凝材料 制备的净浆试块强度接近混凝土试块的强度 ; 碱溶液 达23 时 ,碱溶液激发废渣粉胶凝材料制备的净浆 试块强度接近于混凝土试块的强度 。 3 碱溶液-粉煤灰等废渣可以配置出 28 d 抗压 强度达 44 MPa,抗折强度达 8. 3MPa 同时具有良好工 作性能的钢渣路面混凝土 。 参考文献 1 冯乃谦. 实用混凝土大全. 北京 科学出版社, 2001. 2. 2 S. C. Pala, A. Mukherjeeb, S. R. Pathakc , Investigation of hydraulic activity of ground granulated blast furnace slag in concrete Cement and Concrete Research,2003. 33 1481～ 1486. 3 P. J. Wainwright,N . Rey , The influence of ground granulated blast furnace slag GGBS additions and time delay on the bleeding of concrete, Cement whereas Fe2 has inhibition to this reaction. DYB1 Dian Yuan Bacteria 1 in the course of breeding it with Fe2as the energy can turn Fe2 into Fe3 effectively. Combining this functionwith the above -mentioned reaction can keep on the constant concentration of Fe3and maintain circulation of desulfuration. Keywords flue gas desulfurization, Fe3catalysis, microoganism and coordinate effect STUDY ON SKEW GAS FLOW DISTRIBUTION OF ELECTROSTATIC PRECIPITATOR WITH CFD Dang Xiaoqing et al 45 Abstract On the basis of discussing effect of electrostatic precipitation gas flow distribution on dedusting efficiency, it is introduced skew gasflow technology which can reduce reentrainment and improve the efficiency effectively;and the gas flow distribution in electric field is simulated numerically using CFD, which provides a adjusting and parameters of distribution devices that realizing skew gas distribution in electric field. Keywords electrostatic precipitator, gas flow distribution, skew gas flow technology and CFD EXPERIMENTAL STUDY ON CIRCULATING FLUIDIZED BED BOILER DESULFURATION Ma Linzhuan et al 47 Abstract It was conducted that an industrial test of adding limestone to a circulating fluidized bed CFBboiler 75 t h. The effects of Ca S ratio, bed temperature and suphur content of the coal etc on the desulfuration efficiency were obtained when high -sulphor hard coal was combusted. The optimal Ca S ratio and control parameter of desulphuration under actual operation of CFB boiler were also proposed based on the analysis of the test results. Keywords desulphuration, Ca S ratio, CFB boiler and hard coal DEVELOPMENT AND APPLICATION OF AXIAL FAN AT HIGH TEMPERATURE IN WET ARRESTING DUST OF SHAFT CEMENT KILNLiu Jianshou et al 51 Abstract The article introduces a new axialfan used athigh temperature and high moisture and high dust. Itmakes use of structure ofwater cooling and lubrication and protected belt and clean dust door and so no. It features huge diameter, enormous wind and low pressure. Keywords axial fan used in high temperature, shaft cement kiln, wet arresting dust, water cooling and lubrication ANALYSIS OF CHARACTERISTICS OF VERTICAL WELLS AND HORIZONTAL COLLECTORS USED IN LANDFILLZhu Yan et al 53 Abstract Characteristics of two different suction systems for landfill gas in the largest landfill site of Europe are investigated. Based on field testing and data analyzing, the characteristics such as quality and quantity of the landfillgas, the suction pressure, construction and operation costs are discussed. The advantages and disadvantage of the two systems and their applicability are also summarized. The results are helpful to researchers and engineers in developing countries for their new landfill design and construction. Keywords landfill gas LFG, suction system, verticalwell and horizontal collector EXPERIMENTAL STUDY ON SOLIDIFYING FLY ASH FROM REFUSE INCINERATION BY FUEL MELTINGZhao Guangjie et al 56 Abstract Fly ash from refuse incineration is solidified in a melting furnace that takes diesel fuel as its fuel, the solidifying effect is examined. The influence of different environments on the solidifying effect is also explored. The results show that the fly ash has no toxicity after its melt solidification; acidic pH≤4. 5and alkaline pH≥11. 5environments have a greater effect on the solidification, whereas a wet one hasno obvious effect on the solidification. Keywords fly ash from refuse incineration, melt, solidification and leach toxicity RESEARCH ON THE EFFECT OF LEACHATE RECIRCULATION TECHNOLOGY ON GAS PRODUCTIONBY SEMI-AEROBIC LANDFILLHuang Qifei et al 59 Abstract A simulated large scale landfill was established according to the semi -aerobic landfilling theory. A tracer monitoring for the landfill gas concentration variation on the condition of leachate recycling as compared with that of the un-recycling in semi -aerobic landfill. The results shows that leachate recycling in semi-aerobic landfill reduces the amount of leachate, and does not cause the accumulation of NH 4-N concentration. On the other hand, leachate recycling in semi -aerobic landfill can cause the velocity of methane production faster. The methane concentration in leachate recycling system doubled than the un -recycling one. So it does good to accelerate the stabilization of landfill. Keywords semi -aerobic landfill, leachate recycling, municipalwaste solid and methane THE DESIGN AND APPLICATION OF FLY ASH -SLAG PAVEMENT CONCRETE WITHOUT 4 ENVIRONMENTAL ENGINEERING Vol. 23, No. 5,Oct. , 2005 PROTLAND CEMENTZhou Jia et al 63 Abstract It is presented that alkali activatedslag pavement concrete AASPCismade by activating industrial slag such as steel slag , slag and fly ash etc without any Portland cement as binder and using GGBS gravel and GGBS sand in place of natural gravel and sand as the fine and coarse aggregates. The effect of the proportion of alkali solution on the strength of AASPC is studied. The results show thatwith proper workability the 28 d compressive strength of 44 MPa, bending strength of 8. 3 MPa are obtained. Keywords fly ash, pavement concrete, steel slag , slag and alkali -activated THE EXISTING PROBLEMS OF DETERMINING MICRO -AMMONIA BY NASHI REAGENT COLORIMETRY AND THE SUGGESTIONS ON IMPROVEMENTZhang Surong et al 65 Abstract It is discussed the existing problems of determining micro -ammonia by Nashi reagent colorimetry in the determination of micro- ammonia, it is given the path to lower the s detection limit through reducing the volume of absorbing liquid and adding the sampling volume, and the problem of the overhigh detection limit in the determination of micro -ammonia is solved. Keywords Nashi reagent colorimetry , micro -ammonia, problem and suggestion on improvement APPLICATION OF GRAY RELATIONAL ANALYSIS OF PROMOTING CLEAN PRODUCTION IN ECO-INDUSTRIAL PARKLin Jiquan et al 67 Abstract Clean production is the precondition of construction of an eco-industrial park. Full realization of clean production must be promoted step by step in the exising reconstructive eco -industrial parks. The gray relational analysis was applied in the assessment of promoting clean prouction in an existing reconstructive eco -industrial park. The indicator system and criterion of assessment were set up. The present, medium-term and long term schemeswere respectively set down by the gray relational grade. At the same time, the main problems that restrain the improvement of clean production level of every enterprise were found out by gray relational coefficient. Taking coking enterprises in LongmenIndustry Park for example, the results show that the gray relational grade of No. 4 and No. 9 enterprises exceed 0. 8, in which experiments of carrying out clean production were made, that is to say, they are schemes of promoting clean production at present, and the enterprises are selected in the future, which is the scheme of higher cost for the park. The is a very useful one for assessment of guiding clean production promotion in eco -industrial park with the advantages of uncomplicated principle and reliable results. Keywords clean production promotion, eco -industrial park, gray relational grade and gray relational coefficient APPLICATION OF THE COMBINED TRAPEZOID SPRAY TRAY IN REING SOURWATER STRIPPING COLUMNZhang Wenlin et al 71 Abstract This paper introduces the operational perancesof the combined trapezoid spray tray CTST . In the technical reconstruction of the sour water stripping column for oil refineries, this tray was used instead of F1 float tray in the same column shell. After the technical reconstruction, the treating capacity was increased by more than 80, and the ammonia content of the purified water at the column bottom was lower than 50 mg L. Keywords tray, CTST , stripping column, sour water and technical reconstruction ANALYSIS OF FACTORS AFFECTING PHOSPHORUS REMOVAL EFFICIENCY OF TRIPLE OXIDATION DITCH PROCESSCao Guoping et al 74 Abstract The factor influencing the efficiency of phosphor removal from triple oxidation ditch in Tangshan North Suburb Wastewater Treatment Plant was studied. The result showed that the supernatant reflux from sludge thickener is the main factor causing the low efficiency as well as no anaerobic condition. Some improving processes are also proposed. Keywords triple oxidation ditch, running way, anaerobic phosphorus releasing , aerobic phosphorus absorption and phosphorus removal THE INFLUENCEOFSULFATEREDUCTION ON DENITRIFICATIONUNDER ANOXIC CONDITIONWei Hua et al 76 Abstract It has been conducted an experimental study on the effect of sulfate reduction ondenitrificationunder anoxic condition. The results have demonstrated that the efficiency, the rate and the course of the denitrification processhave been changedby the sulfate reduction process. The efficiency of denitrification decreased from 100 to 81. 4 when the concentration of sulfate was increased. The maximum denitrification rate ranged from 6. 428 mg L min to 4. 04 mg Lmin when the concentration of sulfate solutionwas varied from 0 mg L to 2 000 mg L. Accordingly, the results have shown that the ammonia nitrogen was accumulated during the denitrification process which has been changed by the sulfate reduction process. Keywords sulfate reduction, d