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低碳超高性能混凝土单轴受压力学性能
Mechanical Properties of Low-carbon Ultra-high Performance Concrete under Uniaxial Compression
To tackle the high carbon emissions issue resulting from doubling the cement dosage in ultra-high performance concrete (UHPC), a low-carbon ultra-high performance concrete (LC-UHPC) was developed by replacing a large proportion of Portland cement with granulated blast furnace slag, fly ash, and silica fume. Eleven groups in a total of 154 specimens were fabricated with three factors, namely, cement replace ratio, steel fiber volume content, and water-binder ratio taken into account. Through cube compression tests at different ages, flexural tests, and uniaxial compression tests, the mechanical properties of LC-UHPC, including failure patterns, basic strength, and deformation capacity, were analyzed. Based on the test results, a mathematical equation for the stress-strain curve under uniaxial compression was derived. Results indicated that the LC-UHPC displays shear failure mode under uniaxial compression. Moreover, the addition of steel fibers significantly enhances the mechanical properties of LC-UHPC. Compared with conventional UHPC, up to 70% of the cement in LC-UHPC can be replaced, and its 28-day compressive strength can reach 149.09 MPa. The established axial stress-strain equation can accurately predict the mechanical responses of LC-UHPC under uniaxial compression. This equation provides valuable insights for studying the mechanical properties of LC-UHPC and the design of related structural components.
超高性能混凝土 / 低水泥含量 / 单轴受压试验 / 力学性能 / 应力-应变关系
low carbon ultra-high performance concrete / low cement content / uniaxial compression test / mechanical properties / stress-strain relation
| [1] |
韩冰, 曹黎颖, 康明. 矿渣粉作为水泥混合材及混凝土掺合料的减碳功能分析[J]. 上海建材, 2023(2):25-28.
(
|
| [2] |
孙跃东, 肖建庄. 再生混凝土骨料[J]. 混凝土, 2004(6):33-36.
(
|
| [3] |
|
| [4] |
王峥, 郭振伟. 双碳目标下减碳固碳建筑材料展望[J]. 建设科技, 2021(19):53-56.
(
|
| [5] |
陈登, 宋旭艳, 何智海. 煅烧渣土-白云石对水泥砂浆强度和膨胀性能的影响[J]. raybet体育在线
院报, 2021, 38(1): 146-150.
采用渣土对白云石进行煅烧改性,研究了煅烧渣土-白云石对水泥砂浆强度和膨胀性能的影响规律,并采用X射线衍射仪、扫描电子显微镜和能谱仪研究了掺煅烧渣土-白云石水泥的水化产物性能。结果表明:煅烧渣土-白云石可生成β-C<sub>2</sub>S和C<sub>12</sub>A<sub>7</sub>,且随着煅烧温度的提高,β-C<sub>2</sub>S和C<sub>12</sub>A<sub>7</sub>的含量增加;煅烧渣土-白云石能够有效促进复合水泥砂浆后期强度的发展,其中掺10%煅烧渣土-白云石水泥砂浆的90 d强度甚至高于纯水泥砂浆;此外,煅烧渣土-白云石中的MgO可水化生成Mg(OH)<sub>2</sub>,固相体积增加,促进了水泥砂浆的膨胀,且膨胀率随着煅烧渣土-白云石掺量的增加而增加。研究成果对于提高白云石在水泥混凝土中的应用及减轻建筑垃圾对环境的污染有一定参考价值。
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Dolomite was modified through calcination mixed with muck. The effects of calcined muck-dolomite on the strength and expansion properties of cement mortar were investigated. The hydration products of cement containing calcined muck-dolomite were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). Results show that β-C2S and C12A7 were generated in calcined muck-dolomite, and the content of β-C2S and C12A7 increased with the rising of calcination temperature. The incorporation of calcined muck-dolomite improves the strengths of blended cement mortar effectively at later age. Cement mortar containing 10% calcined muck-dolomite even gain a higher strength at 90 d than pure cement mortars. In addition, the hydration of MgO in calcined muck-dolomite gave rise to Mg(OH)<sub>2</sub>, resulting in the expansion of cement mortars, and the expansion rate augmented with the increase of dosage of calcined muck-dolomite. The research finding is of referential value for promoting the application of dolomite in cement concrete and for reducing the pollution of construction wastes.
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| [6] |
董伟, 苏英, 林艳杰, 等. 粉煤灰对再生混凝土抗碳化性能的影响[J]. raybet体育在线
院报, 2019, 36(9):142-145.
粉煤灰再生混凝土符合“十三五”规划绿色发展理念,粉煤灰及再生骨料等废弃物的有效利用具有重大的经济意义和环保意义。试验设计了不同粉煤灰掺量(0%,15%,25%,35%,45%)的再生混凝土,研究粉煤灰再生混凝土的碳化规律,并建立碳化预测模型。结果表明:混凝土的碳化深度与碳化时间及粉煤灰掺量呈正比关系;CO<sub>2</sub>扩散系数与粉煤灰掺量呈线性函数关系。建立了基于CO<sub>2</sub>扩散系数的碳化深度预测模型,模型的建立为粉煤灰再生混凝土的应用提供了重要支撑。
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Adding fly ash in recycled concrete accords with the concept of “The 13<sup>th</sup> Five-Year Green Development Plan”. The reasonable use of fly ash and recycled aggregate wastes is of great significance for economy and environment. In this research, we designed recycled concrete specimens dosed with different content of fly ash (0%, 15%, 25%, 35% and 45%) to investigate the rule of carbonization of recycled concrete mixed with fly ash. Results demonstrate that the carbonization depth of concrete is in positive relation with carbonizing age and fly ash content; the coefficient of CO<sub>2</sub> diffusion is in a linear functional relation with fly ash content. Moreover, we built a prediction model for carbonization depth based on the coefficient of CO<sub>2</sub> diffusion.
|
| [7] |
闫海峰, 赵更歧. 铜矿尾矿取代部分水泥对混凝土性能的影响[J]. raybet体育在线
院报, 2023, 40(10):160-166.
矿物加工过程产生的尾矿是主要的全球性环境问题之一。这些尾矿在环境中积累,会对周边地区造成重金属污染。为探讨尾矿在混凝土中的再利用,以铜矿尾矿部分替代水泥应用于混凝土的制备中,对制备的混凝土试样进行抗压强度、抗氯离子渗透性能、固体废弃物毒性浸出(TCLP)和X射线衍射(XRD)测试。结果表明:试样抗压强度随铜矿尾矿置换率的增加而降低,且早期抗压强度损失较大。龄期为28 d时,与普通混凝土相比,铜矿尾矿置换率10%~40%的试样抗氯离子渗透能力提高,而置换率50%~60%时降低,当龄期增加到90 d时,含铜矿尾矿试样的抗氯离子渗透能力均提高。金属通过参与水泥反应,以金属氢氧化物的形式沉淀或存在于水泥晶体中进一步稳定,所有含铜矿尾矿试样中重金属的浸出质量浓度均低于标准限值。
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Tailings, a byproduct of mineral processing, pose a significant global environmental issue. These waste materials accumulate and contaminate the surrounding areas with heavy metals. To explore the possibility of reusing tailings in concrete, we selected copper mine tailings as a partial substitute for cement in concrete preparation, and performed tests on concrete samples to assess the compressive strength, resistance to chloride ion penetration, Toxicity Characteristic Leaching Procedure (TCLP), and X-ray diffraction (XRD). The findings revealed a substantial loss of early compressive strength, and also a decline of compressive strength with higher replacement rates of copper tailings. At the age of 28 days, compared to ordinary concrete, samples containing 10%-40% copper mine tailings exhibited improved resistance to chloride ion penetration, whereas those with 50%-60% copper mine tailings displayed a decrease. However, at the age of 90 days, the resistance to chloride ion penetration of all tailings samples improved. This improvement can be attributed to the participation of copper mine tailings in cement reactions, resulting in the stabilization of metals through metal hydroxide precipitation or their presence within cement crystals. Moreover, the leaching rate of heavy metals in all copper mine tailings samples was within standard limit.
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| [8] |
陈佩圆, 何士成, 王鹏举, 等. 高掺量矿渣砂浆的力学强度、耐久性及生态效率评价[J]. raybet体育在线
院报, 2021, 38(7): 115-119, 124.
为充分发挥矿渣混凝土的绿色环保的优点,加快高掺量矿渣混凝土的应用,使用矿渣取代80%水泥制备了矿渣生态砂浆,利用硅粉作为基本性能调控材料,研究了硅粉掺量与矿渣砂浆力学和耐久性能的关系,并评价了矿渣砂浆的生态效率。研究结果表明,硅粉有助于缓解高掺量矿渣砂浆的缓凝问题,在10%硅粉掺量下,矿渣砂浆的凝结时间与基准组相近。另外,硅粉可显著改善矿渣砂浆的力学强度和耐久性,在最优掺量组 (5%)中,矿渣砂浆的28 d抗压强度和抗折强度均高于基准组。矿渣与(2.5%~10%)硅粉复掺时,砂浆的毛细吸水率降幅为8.83%~26.81%,电通量降幅为5.28%~36.87%。本研究通过使用矿渣和硅粉共同取代80%水泥,有效改善了矿渣砂浆的基本性能,提升了其生态效率,可为矿渣生态混凝土的应用与发展提供理论依据。
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To make full use of the prominent green feature of slag concrete and accelerate its practical application, we adopted silica fume as the strength adjustor to investigate its effect on the mechanical strength and durability of mortars with 80% slag. We also evaluated the ecological efficiency of slag mortars. Experimental results demonstrate that silica fume is such an effective material to mitigate the retarded setting of mortars with high amount of slag due to dilutive effect. When 10% silica fume was added, the setting time of slag mortar was close to that of the control group. Moreover, silica fume has exerted prominent effects on the mechanical strength and durability of mortars. With 5% silica fume added, both the 28-day compressive strength and the flexural strength of mortar were much higher than those of mortar without silica fume. Consequently, the durability of mortar was also greatly improved by incorporating slag and silica fume into mortars, i.e., the capillary water absorption and electric flux of mortar reduced 8.83%-26.81% and 5.28%-36.87%, respectively. In summary, through the combined use of slag and silica fume as the alternative to 80% cement to prepare mortars, we significantly ameliorated the performance of slag mortars as well as its ecological efficiency, hence providing theoretical basis for the application and development of concrete with high volume of slag.
|
| [9] |
陈国灿. 低碳超高强石渣混凝土的配制技术研究[J]. 湘潭大学自然科学学报, 2010, 32(4): 58-63.
(
|
| [10] |
陈倩. 钢-聚丙烯混杂纤维超高性能混凝土单轴受压应力-应变关系研究[D]. 武汉: 武汉大学, 2020.
(
|
| [11] |
|
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
GB/T 51366—2019, 建筑碳排放计算标准[S]. 北京: 中国建筑工业出版社, 2019.
(GB/T 51366—2019, Standard for Building Carbon Emission Calculation[S]. Beijing: China Architecture & Building Press, 2019.) (in Chinese)
|
| [16] |
GB/T 50081—2019, 混凝土物理力学性能试验方法标准[S]. 北京: 中国建筑工业出版社, 2019.
(GB/T 50081—2019, Standard for Test Methods of Concrete Physical and Mechanical Properties[S]. Beijing: China Architecture & Building Press, 2019.) (in Chinese)
|
| [17] |
JGJ/T 15—2021, 早期推定混凝土强度试验方法标准[S]. 北京: 中国建筑工业出版社, 2021.
(JGJ/T 15—2021, Standard for Test Method of Early Estimating Compressive Strength of Concrete[S]. Beijing: China Architecture & Building Press, 2021.) (in Chinese)
|
| [18] |
侯永利, 郑刚. 再生骨料混凝土不同龄期的力学性能[J]. 建筑材料学报, 2013, 16(4): 684-687.
(
|
| [19] |
陕亮, 张亮. 混杂钢-聚丙烯纤维混凝土的试验研究与强度计算[J]. raybet体育在线
院报, 2015, 32(12): 114-119.
为探究混杂钢-聚丙烯纤维混凝土力学性能,基于复合材料强度理论,在试验研究的基础上,对混凝土强度对比试验结果进行数值分析,并根据试验结果规律,给出了混杂钢-聚丙烯纤维混凝土立方体抗压强度、劈裂抗拉强度和轴心抗拉强度的计算式,以及各强度间的关系。通过数理统计方法分析研究了混杂纤维混凝土中纤维体积率、长径比对强度的影响,确定了计算模式中的待定参数。从强度计算式中不同纤维对应的影响系数可以看出,对混杂钢-聚丙烯纤维混凝土的强度起决定作用的是钢纤维的体积率和长径比;混杂钢-聚丙烯纤维混凝土的强度计算式与关系式拟合效果良好,可为同行业研究者们和工程应用提供参考。
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On the basis of contrasting experiment results of concrete strength, numerical analysis is carried out to explore mechanical properties of hybrid steel-polypropylene fiber reinforced concrete(HSPFRC).The calculation formulas and relations among compressive strength, splitting tensile strength and axial tensile strength of HSPFRC are proposed based on the theory of composite material strength and the experimental observations. The undetermined parameters in the model are solved by means of statistical method,and the effects of volume fraction of fiber and length-diameter ratio on strength are taken into account for hybrid fiber reinforced concrete. In light of influence parameters of the strength formulas for different kinds of fibers, we can find that volume fraction of steel fiber and length-diameter ratio are vital to the strength of HSPFRC. The calculation formulas and dependence relations are well fitted, so they can be referenced for researchers in the same field and engineering application. |
| [20] |
|
| [21] |
CECS 38—2004, 纤维混凝土结构技术规程[S]. 北京: 中国计划出版社, 2005.
(CECS 38—2004, Technical Specification for Fiber Reinforced Concrete Structures[S]. Beijing: China Planning Press, 2005.) (in Chinese)
|
| [22] |
马亚峰. 活性粉末混凝土(RPC200)单轴受压本构关系研究[D]. 北京: 北京交通大学, 2006.
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