土建材料检测机构管理对检测质量的影响

随着我国城市化建设的不断扩大,促使我国土建工程项目不断增多,然而针对项目的增多,我国土建工程的质量问题也在不断地增多,并且通过相关分析,问题的多数原因都是因为土建材料的不合格而导致,所以要想有效的避免事故的发生,就需要重视起对土建工程材料的检测,此外还需要进一步加大对建筑材料的监控。与此同时,还需要全面假期那个对材料方面的检测,并确保工程材料的整体质量,确保土建工程施工可以顺利的开展。但为了可以保障好土建工程的施工质量,土建材料的检测机构就需要不断的规范检查流程,并且需要切实做到全面对材料进行检查,从而能够保障好材料的质量。基于此,文章主要针对土建材料检测的管理以及对材料质量的检查进行了简要的分析,并根据当前土建材料检测过程中存在的一些问题,提出一些可行性的建议,希望可以进一步加强我国土建工程的整体发展。

浅谈在土建材料加州承载比(CBR值)试验中的一些体会

CBR法是目前世界上使用最广泛的一种方法。文章简单介绍了CBR试验的基本原理、试验目的及试验方法。

乡土建筑材料在生态农业茶园的应用研究——以永川茶山竹海农业园为例

进入二十一世纪,农业发展方面更加注重生态和谐、环境友好,其中茶业发展方面也是如此,致力于在保护生态环境的前提下发展经济。在茶园的发展过程中,现代建筑或多或少会影响当地生态平衡,因而在建设过程中要注重乡土建筑材料的使用,力促于创建一个各方面协调发展的生态茶叶园。本文将以永川茶山竹海农业园为例,探讨乡土建筑材料在生态农业茶园的应用研究。

浅谈交通类院校研究生《材料制备与合成》课程的教学改革

本文立足学校材料科学与工程交通土建材料学科背景,以材料性能与结构为导向,使得《材料制备与合成》课程完成课程定位、教学内容、教学方式与考核等环节的教学改革,有力促进了硕士研究生创新能力的培养和提升。

交通院校材料物理与化学专业硕士点教改探析——以重庆交通大学为例

立足于其本校材料科学与工程交通土建材料学科背景,重庆交通大学研究生材料物理与化学专业完成了从突出办学特色、重构特色课程体系与教学内容、改革课程教学模式、构建特色实践课程、强化"双师型"导师队伍、优化评估考核机制等几个环节的教学改革,有力推动了应用型高素质人才的培养。

如何控制土建施工技术质量

积极寻求有效的土建施工技术质量控制措施,可以助力土建工程建设水平的提升。基于此,本文提出了做好设备准备工作、保证材料质量、充分地开展交底工作、加大培训工作力度、强化施工技术质量通病预防这几项土建施工技术质量控制措施,实现了对土建工程施工的深入分析,希望能为土建工程领域的建设发展提供助力。

关于中俄建安工程材料转化的研究

结合中俄土建及安装工程材料转化的研究现状,介绍了建安工程材料转化的主要范围,并阐述了材质转化与规格转化的方法,有利于节约工程建设成本,为中俄能源合作奠定坚实的基础。

Experimental Research on Behavior of Composite Material Projectile Penetrating Concrete Target

Projectile made of carbon fiber composite material shell and metal warhead penetrates concrete target at speeds of 336,m/s,447,m/s and 517,m/s.The angles between the perpendicu-lar of target surface and projectile axis are 0°and 30°.The thickness of concrete target is 200,mm and the compression strength is 30 MPa.The experimental results indicate that the strength of composite material structure is high.Composite projectile can go through concrete tar-get without fiber segregation and breakage.The percent fill is 18.5% in the composite material projectile.It is about twice as that of metal projectile,if the density of metal is taken as 7.8,g/cm3.Comparing with metal projectile,low-density,high-strength composite material can lessen projec-tile weight,improve charge-weight ratio of detonator and enhance destructive powder.

Experimental Study on Pull-out Behavior of Different Geotextiles

The pullout testing of geosynthetics is essential for studying interface interaction in the soil-reinforcement system. In this paper, a new method for testing interface properties of geotextiles is proposed. The interface frictional characters of two kinds of geotextiles (woven and needle-punched nonwoven) are investigated through pullout test. Nonwoven specimen has more wide variety of displacement along length than that of woven under the same pressure because of their different extensibility. The greater the elongation and deformation of specimens, the more evident the variations of displacement along reinforcement from front to pullout end. The greater the normal pressure, the smaller the displacement of every position along length with the same pullout load. The study focuses on the effects of the tensile modulus and the difference of pullout response between woven and nonwoven geotextiles.

Experimental and theoretical research on residual strength of plain concrete under compressive fatigue loading

To investigate the residual strength of concrete under fatigue loading, experiments were conducted to determine the functional relation between residual strength and the number of cycles. 80 100mm×100mm×100mm specimens of plain concrete were tested under uniaxial compressive fatigue loading. Based on probability distribution of the residual strength of concrete under fatigue loading, the empirical expressions of the residual strength corresponding to the number of cycles were obtained. There is a good correlation between residual strength and residual secant elastic modulus. Thus the relationship between residual secant elastic modulus and the number of cycles is established. A damage variable based on the longitudinal maximum strain is defined, and a good linearity relationship between residual strength and damage is found out.

Preparation and characterization of metakaolin-phosphate cement

We prepared cold-setting cement with metakaolin from kaolin dehydrated at 800 ℃ and phosphate, and studied the phase composition, microstructure and setting reaction mechanism of the cementing material by means of infrared spectroscopy, thermogravimetry, X-ray diffraction, and scanning electron microscopy. The metakaolin-phosphate cement is predominantly amorphous, where the phases responsible for chemical setting are mainly amorphous aluminophosphate hydrates. The reactivity of metakaolin depends on the particle size. Metakaolin particles of 1.75 μm in D50 have an acid dissolution index up to 18.45%, and the reaction with phosphate at room temperature to form metakaolin-phosphate cement takes only 6 h. The so obtained cement shows a compressive strength of 92.5 MPa after 7 d and keeps its amorphous phase at 1 000 ℃, demonstrating better bonding and mechanical properties and higher stability at a medium or high temperature.

Spallation Mechanism of RC Slabs Under Contact Detonation

The spallation of the concrete slabs or walls resulting from contact detonation constitutes risk to the personnel and equipment inside the structures because of the high speed concrete fragments even though the overall structures or structural members are not destroyed completely. Correctly predicting the damage caused by any potential contact detonation can lead to better fortification design to withstand the blast Ioadings. It is therefore of great significance to study the mechanism involved in the spallation of concrete slabs and walls. Existing studies on this topic often employ simplified material models and 1D wave analysis, which cannot reproduce the realistic response in the spallation process. Numerical simulations are therefore carried out under different contact blast Ioadings in the free air using LS-DYNA. Sophisticated concrete and reinforcing bar material models are adopted, taking into account the strain rate effect on both tension and compression. The erosion technique is used to model the fracture and failure of materials under tensile stress. Full processes of the deformation and dynamic damage of reinforced concrete （RC） slabs and plain concrete slabs are thus observed realistically. It is noted that with the increase of quantity of explosive, the dimensions of damage crater increase and the slabs experience four different damage patterns, namely explosive crater, spalling, perforation, and punching. Comparison between the simulation results of plain concrete slabs and those of RC slabs show that reinforcing bars can enhance the integrity and shearing resistance of the slabs to a certain extent, and meanwhile attenuate the ejection velocity and decrease the size of the concrete fragments. Therefore, optimizing reinforcement arrangement can improve the anti-spallation capability of the slabs and walls to a certain extent.

Prediction of Flexural Deformation of Reinforcement Concrete Beams with Polynomial Tension Stiffening Model

Based on an assumption of parabolic bond stress distribution,a simplified model with quartic polynomial function of the relative slip of steel bar and surrounding concrete for reinforced concrete (RC)tensile member was proposed. The post-cracking behavior as well as tension stiffening effect was considered in the new model. The relative slip of bending member could also be determined through the extension of the new model,which could be applied to obtaining the concentrated rotations at certain sections in order to predict the flexural deformation of RC beam. Several examples of four-point bending RC beams were approached to verify the new model,and the predictions of the flexural deflections of RC beams agreed well with experimental results. The new model can be extended to the application of partially corroded RC beam.

Preliminary Evaluation of Some Engineering Properties of Laterite as Foundation and Construction Materials in Muglad Basin in Sudan

This paper reports and evaluates the subsurface investigations of lateritic soil in Muglad Basin. Lateritic soil is described as highly weathered and altered residual/transported soil formed by the in-situ weathering and/or decomposition of rocks in the tropical and sub-tropical regions with hot, humid climatic conditions. The field works include excavation of test pits, drilling of boreholes and performing of SRT （standard penetration test）. The engineering properties of soil such as sieve analysis, consistency, compaction test, CBR （California bearing ratio） test are deduced in the laboratory. Lateritic soil is also evaluated to be used as foundation and construction materials. Concretionary lateritic soil is valuable road pavement materials, widely used in the tropics as sub-base, base material and for gravel roads. The term laterite, however, has tended to be indiscriminately applied in tropical highway engineering to any red soil. Lateritic soils in this study area were classified as reddish brown, medium dense to very dense, clayey silty sand with noodles of quartz and gravels. According to laboratory test, the lateritic soil was found to be good as construction materials, and can be used for embankment purposes; on the other hand, blending such materials with gravels can improve the low CBR values.

Renovation of the Centennial Hall

The Centennial Hall was designed as a monumental building entirely of reinforced concrete. Soon it became a model for modernist buildings of that era. During the years 2009-2011, the biggest renovation since its completion took place. All activities described in the following paper aimed to put the Centennial Hall into good repair and adjust it to the applicable requirements of modem public buildings. The primary aim is to preserve the authenticity of the original materials used in construction through the use of remedial technologies, thereby maintaining the historical integrity of the building.

Studying the Properties of Lightweight Concrete Using Construction Materials Waste

The main purpose of this research is to study the mechanical properties of lightweight concrete through the using of different types of lightweight aggregate. Three types of lightweight aggregate were used in this study for the production of lightweight concrete. These types are red block aggregate, red ceramic aggregate and white thermostone aggregate. All these types have been brought from construction waste. A comparison of the properties of lightweight concrete with normal concrete is the most important goal of this study. The most important properties of concrete, which were compared with each other is compressive strength, static modulus of elasticity, splitting tensile strength and slump flow.

Bond Strength of Bamboo Reinforcement in Light Weight Concrete

Bamboo reinforced concrete as a building material is expected to be an alternative to steel reinforced concrete. Due to the fact that steel is not renewable and polluting steel mills are fairly high. The bond strength is a major concern for the natural fiber used as reinforcement in structural composites. This paper reports study on the bond strength of bamboo reinforcement in concrete, to determine the adhesion reinforcement in concrete often do by the pull-out test. The research objective was bond strength of lightweight concrete and bamboo reinforcement. The test used light weight concrete with foam additives klerak. Bamboo slats were coated with paint and sprinkled with sand. The results obtained showed that the bond strength bamboo 60% of the bond strength steel.

Multi-criteria Decision of Type and Building Material for Simple House Construction

Facing the innovation technology in building construction, the designer has the option in selecting the type of system construction and building materials. There is a big question for the designer and owner on how to evaluate the quality material to meet the technical requirements as building construction reliability. By demand to provide a low cost house, there is need for improving structure model and material construction for residents. When material cost takes 60%-70% of total construction cost, it is important to select the appropriate building material. Currently the innovation of material building for main frame and wall component has present for residential projects in Indonesia. Attempt to replace the traditional material such as brick or pozzolan lime concrete block is developed a new material include utilization of coal combustion waste for concrete block, lightweight concrete, or prefab panel wall. This paper presents the research result to develop a tool support for material and system construction selecting that facilitates the selection an optimal material for a simple house construction. A multi-criteria decision method is used based on performance criteria such as economy, reliability, comfort and eco-friend.

Artificial Stone in France （1830-1930）： A Materialbetween Modernity and Tradition

1920s and 1930s architecture has often been associated with the use of modern materials, such as reinforced concrete, glass and steel, mainly thanks to the role given them by the historiography of the modern, of presenting a break with former tradition and of spreading the need of architectural renewal. The study of architecture from the point of view of construction techniques evidences, instead, how architectural renewal started earlier, during the 19 century and involved the whole realm of building, even tradition-associated materials, such as wood and stone. Indeed, artificial stone （which appeared in early 19 century） represents--above all in France--a link between traditional construction in stone and the newborn reinforced-concrete technique, so as to underline the gradual shift from 19 century construction codes to the new industrial construction techniques, which in the 1920s and 1930s tend to overlap and blend, in this way determining a material continuity of modern and 19 century architecture.