Thermal isolation and mechanical properties of fibre reinforced mud bricks as wall materials

2007 ◽  
Vol 21 (4) ◽  
pp. 901-906 ◽  
Author(s):  
Hanifi Binici ◽  
Orhan Aksogan ◽  
Mehmet Nuri Bodur ◽  
Erhan Akca ◽  
Selim Kapur
2016 ◽  
Vol 33 (1) ◽  
pp. 47-56
Author(s):  
Jerzy Trzciński ◽  
Małgorzata Zaremba ◽  
Sławomir Rzepka ◽  
Fabian Welc ◽  
Tomasz Szczepański

Abstract The archaeological site Tell el-Retaba in north-eastern Egypt, about 35 km to the west of Ismailia city, is located in the middle of Wadi Tumilat, a shallow valley running from the Nile Delta to the Bitter Lakes, along which flows the Suez Canal. In ancient times the valley was a route between Egypt and Syro-Palestine, strongly fortified in the New Kingdom times (16th–11th century BC). Mud bricks were analyzed from two parts of the Wall 1 (core of grey-brown bricks and inner extension of green bricks) in a fortress which existed during the Ramesses II times. Grain-size composition of the studied bricks was almost identical in both parts of the wall, suggesting the same source material for a production of brick. However, significant differences were observed in physical and mechanical properties (uni-axial compressive strength) in both types of bricks. Bricks from the core had lower bulk density, higher porosity and soak faster, whereas their resistance parameters were much lower than those of the bricks from the inner extension. The reason for such large differences in brick properties was a technology of their production, particularly proportion of components, water volume added during brick formation or density degree. Brick preparation and in consequence, physical-mechanical properties had direct influence on preservation of defensive structures during environmental changes related to changes of groundwater and surface water levels or of precipitation. Ancient Egyptians responsible for construction works in mud brick structures of the fortress must have had good knowledge and experience. This could be observed particularly for the heaviest and most important construction element that is the defensive wall, founded on well-densified deposits. It was also testified by higher resistance of green bricks from the inner extensions, which probably originated slightly later and were intended to reinforce a weaker core built of grey-brown bricks.


2012 ◽  
Vol 174-177 ◽  
pp. 787-790
Author(s):  
Feng Hu ◽  
Chao Chao He ◽  
Min Xu

Based on the experimental study of the shear performance of three brand-new types of masonry brick wall and through the comparison of their shearing resistance by examining respective intrinsic factors, this essay aims to provide some reliable mechanical properties of these wall materials for their practical application in engineering and moreover offers some basic references for their popularization and application.


2011 ◽  
Vol 250-253 ◽  
pp. 2024-2031
Author(s):  
Ri Gao Chen ◽  
Yan Yao ◽  
Ling Wang

Recycle utilization of building waste is the tendency of building material for environment protection & sustainable development. Mechanical properties of molded products using building waste (MPBW) were investigated. The main parameters are focus on molded pressure, dosage of building waste added into cement and fly ash. The results of experiments showed that molded products using concretes debris as fine aggregates have stronger mechanical properties. The strength of product increased along with molding pressure increase under 15MPa , but it was almost no increase when the molding pressure was up from 15MPa to 20MPa.The addition of building waste has little effect on the compressive strength of product when its dosage range from 50% to 100% .The strength of product had obviously changed after using fly ash partially substitute for cement, when fly ash replace two thirds cement, the product strength of 28d was 15.4MPa, and was still higher than that of the normal wall materials. Later strength of the product had markedly increased, its 180d compressive strength achieved 25.2MPa. Test results confirmed: using building waste, panel, block and other products with better mechanical properties could be manufactured by adjusting the molded pressure and the dosage of building waste and fly ash.


Author(s):  
Noé Mota-Solis ◽  
Mauricio Pelcastre ◽  
Eduardo Ruiz ◽  
Philippe Darcis ◽  
Jose Enrique Garcia-Gonzalez ◽  
...  

The needs for oil and gas exploration in deep water (DW) and ultra-deep water (UDW) severe environments involve critical requirements of heavy wall materials. Offshore DW and UDW impose demanding service conditions of sour environment, mechanical properties, fatigue performance, gas service, high pressure and wide temperature ranges not only for heavy wall seamless line pipe materials but also for the girth weld performance. Thus, the development of heavy wall materials for severe applications is essential for DW and UDW, where complex material requirements are sought. Additionally the girth welding of heavy wall materials has imposed particularities typical of large wall thickness materials’ welding. The latter requires the development of particular solutions for pre-production and GMAW narrow groove offshore welding procedures. The present work presents the development of two welding processes of a heavy wall seamless pipe material: 273.1 mm OD × 46 mm WT, X65 steel grade. Pre-production welding involves STT®+SAW using a dual slope V-bevel, filler material for root processing was an AWS ER80S-G, while welding deposition for fill and cap passes was made using twin-wire technique, with two different electrodes (ENi1K and EG AWS designations), in combination with a neutral flux. On the other hand, narrow groove welding procedure considered a J-bevel, 3° angle, applying STT®+GMAW; filler material for GMAW was as well an ER80S-G AWS designation. Both welding procedures are aimed to deliver adequate mechanical properties to meet sour-service requirements (<250HV10), weld metal overmatching (120 MPa minimum) and toughness (CVN 45JAVE/38JIND) at low temperature. Mechanical characterization included hardness Vickers measurements using a 10 kgf load, tensile tests in all-weld metal and transverse impact fracture Charpy V-notch tests and CTOD tests.


Author(s):  
S. Fujishiro

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.


Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).


Author(s):  
D. R. Clarke ◽  
G. Thomas

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.


Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.


Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.


Author(s):  
H.-J. Kleebe ◽  
J.S. Vetrano ◽  
J. Bruley ◽  
M. Rühle

It is expected that silicon nitride based ceramics will be used as high-temperature structural components. Though much progress has been made in both processing techniques and microstructural control, the mechanical properties required have not yet been achieved. It is thought that the high-temperature mechanical properties of Si3N4 are limited largely by the secondary glassy phases present at triple points. These are due to various oxide additives used to promote liquid-phase sintering. Therefore, many attempts have been performed to crystallize these second phase glassy pockets in order to improve high temperature properties. In addition to the glassy or crystallized second phases at triple points a thin amorphous film exists at two-grain junctions. This thin film is found even in silicon nitride formed by hot isostatic pressing (HIPing) without additives. It has been proposed by Clarke that an amorphous film can exist at two-grain junctions with an equilibrium thickness.


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