Iron tailings powder (ITP) is a kind of solid waste, which pollutes the environment, without any treatment. The application of ITP in cement concrete is a good choice. In this study, the influence of ITP on the flowability, compressive strength, chloride ion permeability and the attenuation of the performance of cement concrete during freeze–thaw cycle (F-T) damage are investigated. An X-ray diffraction, an analysis of the pores and a scanning electron microscope (SEM) are obtained to analyze the mechanism of cement concrete’s performance. The results show that the addition of ITP can decrease the flowability of fresh cement concrete. Cement concrete with a 7% ITP to mass ratio of the total aggregate shows the highest compressive strength and the minimum chloride ion permeability. The relative dynamic modulus of the elasticity of the specimens with 7% ITP during the F-T is the highest. The corresponding mass loss rate is the lowest. The mercury intrusion analysis results show that the pore volume of the specimens with 7% ITP is the lowest. The SEM results confirm that the specimens with 7% ITP show the densest microstructures.
2023年11月9-10日,中国混凝土与水泥制品协会水泥混凝土管涵分会第二次会员代表大会暨行业技术交流会在山东青岛召开.来自行业企业、地方协会的领导、专家及媒体代表等近400人参加了会议.大家集聚一堂,为管涵行业高质量发展建言献策;共商共讨,为分会健康发展谋篇布局.
Sand is one of the main raw materials for concrete preparation,and its mechanical properties and structural stress response state are related to the strength and stability of concrete structure.Therefore,it is of great practical significance to study the basic mechanical properties and structural stress response state of sea sand concrete.In this paper,the control variable method is adopted to determine that other components of the concrete structure are completely consistent,only the type of mixing sand is changed,and the workability,compressive strength and elastic modulus changes of ordinary river sand concrete and sea sand concrete are compared,and the actual mechanical characteristic parameters obtained by analysis are combined.Midas finite element analysis software is used to establish the finite element analysis model of concrete column compression,and the numerical simulation of concrete column compression process is carried out to study the influence of river sand and sea sand on the stress,displacement,deformation and critical load of concrete column.The results show that the sea sand has an effect on the workability,compressive strength and elastic modulus of concrete,especially on the sea sand concrete with strength of C30 and C20.The slump decreases about 31.1%on average,the strength decreases about 10.9%on average,and the elastic modulus increases 17.8%and 5.3%respectively.Under the action of vertical load,the displacement and deformation of sea sand concrete column are larger,and the critical coefficient of buckling load of the main structure is reduced by 19.3%compared with that of ordinary concrete column.
说她"年少",是因为这是一家刚成立8年,十分"年轻"的企业.青岛环球重工科技有限公司(以下简称"环球重工")成立于2015年,是青岛环球集团旗下的全资子公司.公司牢牢锚定"为新型绿色建筑构件制造企业提供智能制造系统解决方案"这一宗旨,现已发展为集盾构管片模具、风电混塔模具、装配式地铁站模具、轨道板模具、智慧梁场模具、整体箱涵模具及各类自动化生产线制造销售于一体的工程装备制造公司.
The industrial sector is the main field of carbon emissions in China,and the building materials industry is an important basic industry for China's national economy and social development.It is also a key industry for energy consumption and carbon emissions in the industrial sector.Under the"carbon peaking and carbon neutrality"goals,accelerating low-carbon transformation is the responsibility of the building materials industry for the dual carbon work.Promoting the greening of building materials has become a trend,and green buildings and green building materials continue to develop.Among them,green certification is an important certification evaluation method for the future mortar industry,the research and promotion of green certification work directly affect the future green development direction of China's mortar industry.This article focuses on the development process of green certification for mortar products,starting from the relevant policies of green certification in China,analyzes and explores the current status and future development trends of green certification work for mortar products.
