检索结果-南通市图书馆

Methodology for the estimation of expansive cement borehole pressure

International Journal of Mining Science and Technology 2023年第1期33卷 73-81页

作者： Kelly-Meriam Habib Isaac Vennes Hani S.Mitri Department of Mining and Materials Engineering McGill UniversityMontreal H3A 0E8Canada

This work is part of a multi-phase project which aims to develop a sound methodology for rock fragmen-tation in underground mines using expansive *** specifically,it is the first phase of the project which focuses on laboratory tests to investigate the mechanical performance of expansive cement,also known as soundless chemical demolition agents(SCDA).This paper reports the results of laboratory tests conducted on instrumented thick-walled cylinders filled with expansive *** pressure evo-lution and temperature variation with time are first examined for different borehole *** clas-sical analytical method for expansive pressure estimation is validated with direct pressure measurement using high-capacity pressure sensor,and an empirical model is obtained.A new methodology based on iterative procedure is developed using axisymmetric finite element modelling and test results to derive the modulus of elasticity of the expansive cement at peak *** results of this study show that the expansive pressure increases with borehole diameter when the rigidity of the steel cylinder is constant reaching 83 MPa for a 38.1 mm *** is also shown that the expansive pressure decreases signif-icantly with increased cylinder rigidity for the same borehole *** newly developed methodol-ogy revealed that the modulus of elasticity of expansive cement at peak pressure is estimated at 8.2 GPa.A discussion on the extension of the findings of this work to hard rock mining applications is presented.

关键词： Rock fragmentation Soundless chemicaldemolitionagents expansive cement

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Hydration Characteristics and Expansion Machanism of expansive cement at Low W/B Ratio

引用

Journal of Wuhan University of Technology(Materials Science) 2003年第4期18卷 80-83页

作者：吕林女 Wuhan University of Technology

The hydration characteristics and expansion impetus of three kinds of cement paste under free- and confined-curing conditions were investigated, which were respectively mixed with three different kinds of expansive agent at low W/B *** results show that the hydration products of pure cement paste and paste mixed with expansive agent are same,but the amount of hydration products,un-hydrated C 3S and C 2S are obviously different at the same hydration *** 3d age,the amount of CH in pure cement paste is less than that of paste mixed with expansive agent,but it is reverse when at 28d *** amount of AFt at 3d and 28d age in pure cement paste is less than those of paste mixed with expansive *** of under free- or confined-curing condition,the amount of ettringite produced varies little since 3d *** joint effect of the tumefaction of gel-ettringite due to water absorption and the expansive pressure on the pore caused by the crystalloid ettringite is the cause of the volume expansion of cement paste,and the former effect is much greater than the latter.

关键词： expansive cement hydration expansion mechanism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mix design and expansion behavior of sulpho-aluminate expansive cementitious composite

引用

Global Geology 2014年第2期17卷 99-104页

作者： MAN Teng WANG Boxin JIN Henan QIU Jianhui College of Construction Engineering Jilin University

Sulpho-aluminate expansive cementitious composite is proved to be one of the most effective ways to prevent concrete cracking too soon. Mix design of sulpho-aluminate expansive cementitious composite completely depends on experience and experiments at present. This method ignores the influence of expansion behavior which hinders the application of sulpho-aluminate expansive cementitious composite. The workability,free expansion property,flexural strength and compressive strength of sulpho-aluminate expansive cementitious composite have been investigated by tests. The relationship between expansion ratio and mix design parameters such as curing age,water-cement ratio and cement abundance coefficient is deduced according to the experimental statistics. A new simplified approach to mix design of sulpho-aluminate expansive cementitious composite is proposed as a reference for construction application,which avoids experiments and experience.

关键词： sulpho-aluminate expansive cement mix design expansive behavior

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A novel V-cut method for explosive-free breakage of biaxially loaded rock using soundless chemical demolition agents

引用

Journal of Rock Mechanics and Geotechnical Engineering 2024年第12期16卷 4866-4877页

作者： Tuo Chen Isaac Vennes Hani S.Mitri Department of Mining and Materials Engineering McGill University3450 University StreetMontrealQuebecH3A 0E8Canada

Interest in soundless chemical demolition agents(SCDAs),also known as expansive cements,as potentially viable alternatives to explosives for rock fragmentation,has been growing in recent ***,there is an increasing amount of literature on the use of SCDA for the breakage of rock blocks and *** research has been conducted so far on the breakage of excavation fronts,such as tunnel or drift faces,using *** is due to the perception that the planar compressive in-situ stresses in the face would inhibit the creation and propagation of fracturing due to expansive *** study proposes a novel V-cut method for demolishing rock panels under biaxial stress using *** method was examined through large-scale tests and numerical *** rock panels were subjected to high biaxial confinements of 26 MPa and 40 *** a level of confinement corresponds to an in-situ stress state 1000 m below the surface in the Canadian *** V-cut drillhole pattern employs two sets of three SCDA holes angled at 45from the face of a Stanstead granite *** drillhole arrangement aims to create a V-shaped wedge in the plane of major principal *** angled drillholes are subjected to expansive pressure,they tend to cast out of the panel face,causing *** panels of 1 m×1 m×0.25 m were successfully demolished using the proposed *** three-dimensional fast Lagrangian analysis code FLAC3D modelling was used to reconstruct the panel failure mechanism owing to the *** study demonstrates the feasibility of fragmenting an excavation front,such as a rock excavation face,with SCDA using a V-cut drill hole pattern while subjected to high biaxial confinement.

关键词： Explosive-free rock fracturing Rock face excavation Biaxial confinements expansive cement Wedge cut Numerical modelling Drift advance

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：