某核电站工程防辐射混凝土施工技术

防辐射混凝土是一种特种混凝土,具有大体积防水混凝土和防辐射混凝土的双重施工难度.结合防辐射混凝土在CPR1000堆型核电站施工中的应用,重点从配合比设计、施工方案选择、施工控制措施几个方面,对重晶石混凝土、褐铁矿混凝土两种防辐射混凝土加以阐述、总结.     

浅谈防辐射混凝土的裂缝控制

防辐射混凝土对裂缝要求严格,就医院防辐射混凝土的裂缝控制进行了论述。     

防辐射混凝土高温稳定性研究进展

防辐射混凝土由于服役环境的特殊性，需长时间处于高温及高辐射之下，因此防辐射混凝土在高温下的力学性能和辐射屏蔽能力是限制其发展和应用的主要因素。本文从普通混凝土的高温性能、防辐射混凝土高温下的力学性能和辐射屏蔽能力方面对现阶段国内外防辐射混凝土研究进行了总结。结果表明，防辐射混凝土正朝着掺入不同类型的重型骨料以改善混凝土的辐射屏蔽性能、高温稳定性和低成本制备等方向发展。     

谈C60高强防辐射混凝土配合比设计

文章针对某医疗综合楼防辐射混凝土技术要求,结合高强混凝土的设计和施工要求,对C60防辐射混凝土进行设计和试配。试验结果表明,在方案六中,当水灰比为0.29、0.27时,抗压强度能够满足C60设计要求;混凝土容重为2490kg/m3,也基本满足防辐射混凝土要求,从而为防辐射混凝土提供了理论依据和技术参考。     

重晶石防辐射混凝土的试验研究

本文以重晶石为防辐射混凝土的主要原材,介绍了不同地区和不同性质重晶石对防辐射混凝土性能的影响试验,成功的配制了密度范围在在3000kg/m^3～4000kg/m^3,强度范围在30MPa～40MPa的重晶石防辐射混凝土.     

防辐射混凝土的试验研究

本文以重晶石为防辐射混凝土的主要原材料,介绍了不同地区和不同性质重晶石对防辐射混凝土性能的影响试验,成功地配制了密度范围在3000~4000kg/m3,强度范围在30~40MPa的防辐射混凝土。     

防辐射混凝土早期收缩性能研究

试验采用重晶石和铁矿石两种重矿石骨料和配重钢骨料配制了强度等级C30防辐射混凝土,研究不同种类骨料对防辐射混凝土的早期收缩性能影响。结果表明混凝土早期收缩主要发生在加水拌合后的24h内,收缩量达72h总收缩的90%;用铁矿石配制的防辐射混凝土早期收缩大于重晶石配置的防辐射混凝土早期收缩;钢骨料自身弹性模量大且不吸水,掺入到混凝土中可以降低早期塑性收缩。     

厚墙大体积防辐射混凝土无缝施工技术

以某屏蔽要求的剪力墙结构为研究对象,研究厚墙大体积防辐射混凝土无缝施工技术。从配合比设计、无缝施工、模板工程、混凝土工程等角度出发,讨论了厚墙大体积防辐射混凝土浇筑工作,以保证防辐射大体积混凝土浇筑的质量。     

防辐射混凝土高性能化研究进展

针对传统防辐射混凝土的研究现状与问题进行综合分析,从防辐射混凝土的制备技术、施工技术及其辐照条件下其内部结构性能等方面介绍了当前防辐射混凝土的高性能化研究进展与成果,提出了该领域亟待解决的问题,并在此基础上预测其未来发展前景。     

不同骨料防辐射混凝土屏蔽性能试验

为研究不同骨料防辐射混凝土的屏蔽性能以及普通砂石骨料对防辐射混凝土屏蔽性能的影响,选用磁铁矿砂、磁铁矿石、重晶石、重晶石砂、钢珠以及普通河砂和碎石作为骨料,拌制得到四组防辐射混凝土,进行γ射线屏蔽试验。试验结果表明,以磁铁矿砂、钢珠、磁铁矿石作为骨料的防辐射混凝土,屏蔽性能最好;四组防辐射混凝土相互对比,可以发现试验所用的几种骨料当中,钢珠的屏蔽性能最好,磁铁矿和重晶石骨料的屏蔽性能优于普通砂石;在常用屏蔽γ射线的混凝土骨料当中掺入普通河砂和碎石,防辐射混凝土仍然具有良好的屏蔽性能。     

防核辐射混凝土高温稳定性能试验研究

利用综合热分析仪、热膨胀仪、X射线衍射仪及扫描电镜,通过测试防核辐射混凝土中水泥石的热分解过程、高温矿物组成变化、热膨胀性能、高温后抗压强度变化,砂浆的热膨胀性能和混凝土高温后微观形貌变化及抗压强度变化,研究了防核辐射混凝土的高温热稳定性能。结果表明,经700℃高温后,水泥石中C-S-H凝胶网状结构出现破碎,数量减少,其主要矿物组分为CaO、Ca(OH)2、C3S和β-C2S,集料与水泥石界面结构松散,并出现裂纹;40～600℃过程中,水泥石和砂浆呈先膨胀后收缩的变化趋势,且水泥石的热膨胀系数远大于砂浆。     

污泥防辐射功能集料的制备及性能

基于重金属元素对高能射线具有优良屏蔽性能的特点,以含10％(质量分数,下同)钡元素的某化工厂污泥为原材料,辅以高岭土、分析纯化学物质为校正材料,通过对生料的配合比优化设计,在一定的煅烧制度下制备出了重金属离子溶出率小、射线屏蔽性能较好的功能集料.试验结果表明:该集料的表观密度达2.95×103 kg/m3,吸水率达1.57％,抗压强度达82 MPa,Ba离子浸出率低至1 mg/L,线性衰减系数达0.243 9 cm-1,可作为集料替代天然重晶石集料制备防辐射混凝土.     

电磁屏蔽混凝土的发展现状

在介绍电磁屏蔽材料的种类和电磁屏蔽原理的基础上，论述了近年来电磁屏蔽混凝土的发展现状，并展望了电磁屏蔽混凝土的研究趋势和应用前景，最后对电磁屏蔽混凝土的开发与示范进行了阐述。     

Recycling of scale and steel chips waste as a partial replacement of sand in concrete

Modification of concrete properties by the addition of appropriate materials is a popular field of concrete research. This study is focusing on the use of selected waste of iron and steel industry (steel chips and scale) as a partial replacement for sand in the production of concrete. In this research study, concretes were made with steel chips scale (ScC) and (SchC) as substitution for raw sand. Sand was replaced by these waste in different proportions (25%, 50%, 75%, and 100%) by weight of sand.The aim of this study is to investigate the compressive strength and absorption properties for gamma radiation of concrete with steel chips and scale waste as a partial replacement for sand. The tests results obtained from concretes produced with scale and steel chips were compared with those in conventional concrete (CC-0).The experimental results indicate that, the addition of these waste to concrete enhances the absorption of gamma radiation without impairing other technical features of the investigated concrete. The data shows, that the concrete mixed with steel chips have better strength than conventional concrete, while in the case of concrete mixed with scale in excess of 25%, the strength become deteriorated. The linear attenuation coefficient of gamma radiation of concrete with a mixture of scale and steel chips with 75% and 100% was very good while the rest have good and satisfying radiation properties. Consequently, concrete prepared from the iron and steel industry solid waste containing steel chips and scale could be preferred for buildings as shielding concretes against gamma radiation. In this research the thickness of the concrete shield which can be used instead of the conventional concrete was also calculated.     

短碳纤维在石墨低频电磁屏蔽混凝土中的应用研究

介绍了分别掺杂短碳纤维和石墨的电磁屏蔽混凝土的制备,研究了短碳纤维和石墨的含量对混凝土低频电磁屏蔽效能的影响,最后分析了短碳纤维的加入对石墨混凝土电磁屏蔽性能的影响机理,为将来设计高性能低频电磁屏蔽混凝土提供了依据。     

Evaluation of geotechnical characteristics of Lasbela barite deposits of Balochistan,Pakistan, as heavyweight aggregate

A number of medium to small sized barite deposits are located within the Mor Mountain Range, Pakistan. The present study evaluated eight barite deposits from the Lasbela area, Balochistan, Pakistan, representing the different parts of the Mor Range. Evaluation of the barite content and those properties important in the production of heavyweight concrete aggregate indicated that the material would be suitable for the construction of earthquake resistant buildings and for radiation shielding.     

Heat transfer analysis through high-strength borated concrete for use as nuclear reactor biological shield

Heat transfer describes the exchange of thermal energy, between physical systems depending on the temperature and pressure, by dissipation of heat. Addition of borax (Na2B4O7) in the range of 0.5-1% by wt. to concrete improves the gamma radiation shielding capabilities of concrete by around 80% and may also influence the various heat transfer parameters. This work deals with the analysis of the heat transfer through a test specimen comprising a rectangular block of high strength borated concrete with Con Plast 430 as a suitable super-plasticizer, and thereby compute the average value of co-efficient of thermal conductivity (K) for it. Also one-dimensional steady state heat conduction analysis is carried out using empirical formulae and the corresponding results are verified using FEA methods applying ANSYS software.     

铅锌尾矿砂混凝土抗压强度及屏蔽性能试验研究

试验研究了铅锌尾矿砂对混凝土抗压强度及屏蔽性能的影响,为铅锌尾矿砂替代河砂配制混凝土提供一定依据。采用铅锌尾矿砂等体积替代河砂作为细骨料浇筑混凝土试件,铅锌尾矿砂的掺量分别为0、10%、20%、30%、40%、50%、60%,结果表明:在掺量为10%~40%时,铅锌尾矿砂混凝土的立方体28 d抗压强度较普通混凝土均有提升,其中掺量为20%时,强度提升最大,约为8.6%;当掺量为50%~60%时,铅锌尾矿砂混凝土的立方体28 d抗压强度较普通混凝土均有降低,且掺量越大,强度降低越多;尾矿砂中元素成分对混凝土的屏蔽效果有较大影响,不同批次的铅锌尾矿砂配制出来的混凝土屏蔽性能存在差异。