摘要
为探明煅烧凝灰岩对水泥水化产物的影响,借助X射线衍射(XRD)、热重分析(TG)、傅里叶变换红外光谱(FTIR)等测试方法,分析了700 ℃下煅烧不同时间后凝灰岩的矿物组成及其对水泥水化产物和硬化体孔结构的影响.结果表明:煅烧后凝灰岩中的沸石水、结构水和吸附水被脱除,斜发沸石等沸石矿物架状结构发生破坏,形成无定形的SiO2和Al2O3;煅烧凝灰岩有助于水泥中的水化硅酸钙(C‑S‑H)、钙矾石(AFt)和单硫型水化硫铝酸钙(AFm)形成,且降低了C‑S‑H的钙硅比(n(Ca)/n(Si)),消耗了Ca(OH)2,水泥更易发生碳化;水化28 d后,煅烧凝灰岩水泥的孔隙率降低,孔径分布更细,从而提高了水泥强度.
中国水泥工业年碳排放量约为12.3亿t,占总排放量的13%,控制水泥工业碳排放量是实现“双碳”目标的关
P·Ⅰ 42.5基准水泥和凝灰岩均来自土耳其NUH水泥厂,其中P·Ⅰ 42.5基准水泥3、7、28 d抗折强度分别为5.5、6.3、7.8 MPa,抗压强度分别为28.6、36.9、50.8 MPa.两者的化学组成(质量分数,文中涉及的组成、掺量等除特别注明外均为质量分数)和X射线衍射(XRD)图谱分别见
Material | CaO | SiO2 | Al2O3 | Fe2O3 | K2O | Na2O | MgO | TiO2 | P2O5 | SO2 | f‑CaO | Other |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Reference cement | 64.02 | 21.14 | 4.69 | 3.15 | 0.26 | 0.30 | 2.57 | — | — | 2.09 | 0.92 | 1.30 |
Trass | 5.09 | 55.53 | 15.22 | 5.71 | 1.89 | 1.15 | 2.71 | 0.79 | 0.24 | — | — | 11.67 |

图1 基准水泥和凝灰岩的XRD图谱
Fig.1 XRD patterns of reference cement and trass

图2 凝灰岩的TG和DTG曲线
Fig.2 TG and DTG curves of trass
先将凝灰岩原料破碎、混合、缩分,在水泥实验磨中粉磨60 min,得到凝灰岩粉料;再使用孔径0.075 mm标准方孔筛筛分,即得到凝灰岩粉.本试验以内掺形式将凝灰岩粉掺入水泥中,掺量为30%.依据
采用日本理学Rigaku型XRD测定原材料和水泥净浆水化产物的矿物相,测试参数为Cu靶Kα射线、管压为40 kV、管流为30 mA,采用连续扫描方式,扫描范围为5°~85°、扫描速率为5 (°)/min.采用瑞士梅特勒-托利多公司TGA/DSC1/1600型同步热分析系统进行TG分析,精确度为±0.5 ℃.采用美国热电公司Nicolet IS50型 Fourier漫反射红外光谱仪,进行傅里叶变换红外光谱(FTIR)测试,分辨率为4 c

图3 凝灰岩水泥砂浆试件的抗折强度和抗压强度
Fig.3 Flexural and compressive strength of trass cement mortar specimens

图4 凝灰岩在700 ℃下煅烧不同时间的XRD图谱
Fig.4 XRD patterns of trass calcined at 700 ℃ for different time

图5 凝灰岩在700 ℃下煅烧不同时间的红外光谱
Fig.5 FTIR spectra of trass calcined at 700 ℃ for different time
凝灰岩水泥水化3 d的XRD图谱如

图6 凝灰岩水泥水化3 d的XRD图谱
Fig.6 XRD patterns of trass cements hydrated for 3 d

图7 凝灰岩水泥水化7、28 d的XRD图谱
Fig.7 XRD patterns of trass cements hydrated for 7,28 d
凝灰岩水泥的红外光谱见

图8 凝灰岩水泥的红外光谱
Fig.8 FTIR spectra of trass cements
基准水泥和凝灰岩水泥水化28 d时的TG曲线见

图9 凝灰岩水泥水化28 d时的TG曲线
Fig.9 TG curves of trass cements hydrated for 28 d
按照式(
× | (1) |
×100 | (2) |
式中:wCH为Ca(OH)2含量,%; MCH为Ca(OH)2的摩尔质量,g/mol; RCH为Ca(OH)2在350~500 ℃下的质量损失率,%;MH2O为H2O的摩尔质量,g/mol; wCC为CaCO3含量,%; MCC为CaCO3的摩尔质量,g/mol; RCC为CaCO3在600~825 ℃下的质量损失率,%;为CO2的摩尔质量,g/mol.
Sample | RCH | wCH | RCC | wCC |
---|---|---|---|---|
Cement without trass | 4.71 | 19.36 | 3.59 | 8.16 |
Cement with trass uncalcined | 3.92 | 16.12 | 2.69 | 6.11 |
Cement with trass calcined for 15 min | 3.24 | 13.32 | 4.02 | 9.14 |
Cement with trass calcined for 30 min | 3.02 | 12.42 | 4.52 | 10.27 |
Cement with trass calcined for 60 min | 3.35 | 13.77 | 3.40 | 7.73 |
Cement with trass calcined for 120 min | 3.77 | 15.50 | 2.69 | 6.11 |
通过氮吸附法测定凝灰岩水泥的累计孔体积和微孔分布,结果见

图10 凝灰岩水泥的累计孔体积和微孔分布
Fig.10 Accumulated pore volume and micropore distribution of trass cements
分形维数能够反映固体材料表面结构的变化.依据FHH模型,使用氮吸附数据绘制水泥试件的分形维数分析曲线,如

图11 凝灰岩水泥的分形维数分析曲线
Fig.11 Fractal dimension analysis curves of trass cements

图12 4种材料
Fig.12
Sample | Total | |||||
---|---|---|---|---|---|---|
Anhydrous cement | 100.00 | 100.00 | ||||
Uncalcined trass | 4.35 | 95.65 | 100.00 | |||
Trass calcined for 30 min | 0.96 | 55.00 | 44.04 | 100.00 | ||
Cement with trass calcined for 30 min | 46.53 | 21.27 | 23.98 | 8.21 | 100.00 |
结合
(1)凝灰岩在700 ℃下煅烧30 min后,沸石结构塌陷,沸石水、吸附水和结构水逐渐被脱除,硅(铝)氧四面体框架中的铝元素含量有所降低,形成无定形SiO2和Al2O3.
(2)由于凝灰岩中的沸石矿物经过煅烧后,部分
(3)掺加煅烧凝灰岩水泥的孔比表面积更大、孔隙率更小、孔径分布更细、水化产物中的Ca(OH)2含量更低、凝胶相含量更高,从而使得掺加煅烧凝灰岩的水泥砂浆试件的抗折强度和抗压强度均有不同程度的增加,且凝灰岩煅烧30 min的增强效果最佳.
参考文献
郭晓潞, 李寅雪, 袁淑婷.水泥生命周期评价及其低环境负荷研究进展[J].建筑材料学报,2023,26(6):660‑669,677 [百度学术]
GUO Xiaolu,LI Yinxue,YUAN Shuting. Life cycle assessment of cement and its research progress in low environmental load[J]. Journal of Building Materials,2023,26(6):660‑669,677.(in Chinese) [百度学术]
蒋正武,尹军.可持续混凝土发展的技术原则与途径[J].建筑材料学报,2016,19(6):957‑963. [百度学术]
JIANG Zhengwu,YIN Jun. Technical principle and approaches for development to sustainable concrete[J]. Journal of Building Materials,2016,19(6):957‑963.(in Chinese) [百度学术]
GHASEMI A , AMIRI S S, KORAYEM A H, et al. Investigating the potential of trass‑cement binary blend for enhancing microscopic properties, macroscopic performance, and sustainability of cement paste[J]. Construction and Building Materials, 2022, 354:129145. [百度学术]
廉慧珍. 沸石岩火山灰活性的研究[J].硅酸盐学报,2002,30(4):411‑416. [百度学术]
LIAN Huizhen. Studies on pozzolanic activity of zeolite‑tuff[J]. Journal of the Chinese Ceramic Society,2002,30(4):411⁃416.(in Chinese) [百度学术]
李响,石妍,李家正,等.含凝灰岩粉复合胶凝材料抗压强度发展规律[J].建筑材料学报,2017,20(3):435‑438. [百度学术]
LI Xiang, SHI Yan, LI Jiazheng, et al.Compressive strength development of complex binder containing tuff powder[J]. Journal of Building Materials,2017,20(3):435‑438.(in Chinese) [百度学术]
ŞÜKRÜ Y, AHMET Ç. Study of effects of natural pozzolan on properties of cement mortars[J].Journal of Materials in Civil Engineering, 2006, 18(6):813‑816. [百度学术]
ALI G, SIAVASH S A, SAJJAD M, et al. Evaluation of the phase composition, microstructure, mechanical performance, and resistance to acid attack of blended cement paste composed of binary trass‑cement system[J]. Construction and Building Materials, 2022, 333:127356. [百度学术]
MUSTAFA Ç, HAKAN B, VURAL A, et al. Investigation of pozzolanic activity of volcanic rocks from the northeast of the Black Sea[J].Science and Engineering of Composite Materials,2014, 23(3):315‑323. [百度学术]
何仕碧,陈太红,安辛友,等.凝灰岩制备水泥混合材的试验研究[J].硅酸盐通报,2018,37(5):1572‑1577. [百度学术]
HE Shibi,CHEN Taihong,AN Xinyou, et al. Experimental study on preparing cement admixture from volcanic tuff [J]. Bulletin of the Chinese Ceramic Society, 2018,37(5):1572‑1577.(in Chinese) [百度学术]
LIEBIG E , ALTHAUS E. Pozzolanic activity of volcanic tuff and suevite:Effects of calcination[J]. Cement and Concrete Research, 1998, 28(4):567‑575. [百度学术]
GÜNGÖR D, ÖZEN S. Development and characterization of clinoptilolite‑, mordenite‑, and analcime‑based geopolymers:A comparative study[J]. Case Studies in Construction Materials, 2021,15:e00576. [百度学术]
PERRAKI T, KAKALI G, KONTOLEON F . The effect of natural zeolites on the early hydration of Portland cement[J]. Microporous and Mesoporous Materials, 2003, 61(1):205‑212. [百度学术]
BURRIS L E, JUENGER M C G. Effect of calcination on the reactivity of natural clinoptilolite zeolites used as supplementary cementitious materials[J].Construction and Building Materials, 2020, 258:119988. [百度学术]
王辉,张典,陈寅炜,等.红土含量对古建红灰性能的影响及作用机制[J].建筑材料学报,2022,25(10):1055‑1060. [百度学术]
WANG Hui, ZHANG Dian, CHEN Yinwei, et al. Influence of red clay content on the performance of red lime using in ancient buildings and its mechanism[J]. Journal of Building Materials, 2022, 25(10):1055‑1060. (in Chinese) [百度学术]
胡智淇,关岩,毕万利.含镁碳酸盐矿物对硫氧镁水泥耐水性的影响[J].建筑材料学报,2022,25(2):184‑190. [百度学术]
HU Zhiqi,GUAN Yan,BI Wanli. Effect of magnesium carbonate minerals on water resistance of magnesium oxysulfate cement[J].Journal of Building Materials,2022,25(2):184‑190.(in Chinese) [百度学术]
VOSKOV A L, VORONIN G F, KUTSENOK I B, et al. Thermodynamic database of zeolites and new method of their thermodynamic properties evaluation for a wide temperature range[J]. Calphad:Computer Coupling of Phase Diagrams and Thermochemistry, 2016, 66:101623. [百度学术]
PEEEAKI T, KAKALIG, KONTORI E. Characterization and pozzolanic activity of thermally treated zeolite[J].Journal of Thermal Analysis and Calorimetry, 2006,82 (1):109‑113. [百度学术]
CHE C C, GLOTCH T D. The effect of high temperatures on the mid‑to‑far‑infrared emission and near‑infrared reflectance spectra of phyllosilicates and natural zeolites:Implications for martian exploration[J].Icarus, 2012, 218(1):585‑601. [百度学术]
ABO‑EL‑ENEIN S A, HEIKAL M, AMIN M S, et al. Reactivity of dealuminated kaolin and burnt kaolin using cement kiln dust or hydrated lime as activators[J]. Construction and Building Materials, 2013, 47:1451‑1460. [百度学术]
LI N, FARZADNIA N, SHI C J. Microstructural changes in alkali‑activated slag mortars induced by accelerated carbonation[J]. Cement and Concrete Research , 2017, 100:214‑226. [百度学术]
YU P, KIRKPATRICK R J, POE B, et al. Structure of calcium silicate hydrate (C‑S‑H):Near‑, mid‑, and far‑infrared spectroscopy[J]. Journal of the American Ceramic Society, 1999, 82 (3):742‑748. [百度学术]
GRZESZCZYK S, KUPKA T, KALAMARZ A, et al. Characterization of eggshell as limestone replacement and its influence on properties of modified cement[J]. Construction and Building Materials, 2022, 319:126006. [百度学术]
ALI A, SHIMA P, MOSTAFA M. Influence of curing conditions on the mechanical and physical properties of chemically‑activated phosphorous slag cement[J]. Powder Technology, 2016, 288:132‑139. [百度学术]
MA B , LOTHENBACH B. Synthesis, characterization, and thermodynamic study of selected Na‑based zeolites[J]. Cement and Concrete Research, 2021, 148:106111. [百度学术]
WANG K S , LIN K L, HUANG Z Q. Hydraulic activity of municipal solid waste incinerator fly‑ash‑slag‑blended eco‑cement[J]. Cement and Concrete Research, 2001, 31(1):97‑103. [百度学术]
KLINOWSKI J. Nuclear magnetic resonance studies of zeolites[J]. Progress in Nuclear Magnetic Resonance Spectroscopy, 1984, 16:237‑309. [百度学术]
THOMAS J M, KLINOWSKI J. The study of aluminosilicate and related catalysts by high‑resolution solid‑state NMR spectroscopy[J]. Advances in Catalysis, 1985, 33:199‑374. [百度学术]