Papers by Keyword: Strength

Abstract: This study presents an investigation into high-temperature resistance of alkali-activated slag concrete (AASC). Sodium oxide (Na2O) concentrations of 4%, 5% and 6% of slag weight and liquid sodium silicate (SiO2) with modulus ratio of 0.8 ( mass ratio of SiO2 to Na2O ) were used as activators to activate granulated blast furnace slag (GBFS). All cylindrical specimens with the same binder content and liquid/binder ratio of 0.5 were cast and cured in the air, under the saturated limewater and in a curing room at relative humidity of 80% RH and temperature of 60 °C, respectively. Test results demonstrate that the high-temperature resistance of AASC decreased with an increase of temperature. The compressive strength and high-temperature resistance of AASC improved with an increase dosage of Na2O and AASC cured at relative humidity of 80% RH and temperature of 60 °C has the superior performance, followed the AASC by air curing and saturated limewater curing. The higher compressive strength and superior high-temperature resistance have been obtained in AASC than comparable OPC.

Abstract: This paper studies the effects of high-volume composite mineral admixture made of limestone powder and low-quality fly ash on the properties of concrete. Through experiments, this paper makes clear the workability of fresh concrete and analyzes the law of strength development of concrete. The experimental results indicate that the concrete with high-volume limestone powder as composite mineral admixture has good fresh properties; due to low water consumption per unit volume, medium-and-high-strength concrete can be prepared. As new type concrete mineral admixture, the composite mineral admixture made of limestone powder and low-quality fly ash will play an active role in the sustainable development of concrete industry.

Abstract: Xigeda Soil, as a kind of typical soil widespread in west region of Panzhihua, is widely applied to local engineering construction. Limesoil made by adding quicklime into Xigeda soil is also extensively used in wall construction of rural house building. The strength of wall material of Xigeda limesoil wall is measured in this paper through contrast test, meanwhile, strength of rammed limesoil with 1:9 volume ratio is measured on 60th day and 36th month respectively. The test result indicates that compressive strength of limesoil increased by 67% and its tensile strength also greatly increased, which is beneficial to its application in wall engineering construction. This paper also makes an analysis of limesoil mechanism of cementation and points out that Xigeda limesoil is a favorable wall material for house building.

Abstract: The paper assessed the impact of the laser welding speed on the strength and fatigue properties of the aluminum layer found in multilayer pipes. The conducted experiment has shown that during the adjustment of the welding speed one has to take into account not only the results of static tests, but also the results of fatigue tests. The impact of the welding speed on fatigue life depends on the level of stress max. This level is slight in the area of the biggest stresses and increases along with the decrease in stresses.

Abstract: Cu-Ni-Zn/Cu-Zr/Cu-Ni-Zn three layered clad plates were prepared by high pressure torsioning (HPT) at room temperature and theirmicrostructural and mechanical analyses wereperformed. No intermetallic compounds were observed at Cu-Zr/Cu-Ni-Zn interfaces in the as-HPTed and heat-treated Cu/Ni-Zn/Cu-Zr/Cu-Ni-Zn clad plates. The strength of as-HPTed clad plate reached up to 610 MPa with the ductility of 14%. After heat treatment at 500oC, Cu-Ni-Zn/Cu-Zr/Cu-Ni-Zn clad plate exhibited the strength up to 490 MPa and the ductility of 28 %. The clad plate fractured all together at the same time without discontinuous drop of the stress until final fracture. The excellent mechanical reliability and the good interfacialbonding strength can be attributed to the absence of detrimental interfacial reaction compounds between Cu-Ni-Zn and Cu-Zr.

Abstract: The Q235 steel sample was surface-micropored by multicomponent permeating at 923K for 2h, electroless nickel plating at 353K for 2h and sintering at 1223K for 1h. The surface morphology, microhardness distribution, mechanical property and corrosion resistance of samples were analyzed respectively by metallographic analysis, hardness test, tensile test and corrosion test. The result indicates that the surface-micropored process can enhance the surface hardness and corrosion resistance of the Q235 steel sample, while decrease its strength and plasticity at the same time.

Abstract: The compressive strength and the flexural strength of CA mortar at different temperature conditions were all tested. We have found that temperature has great influence on the mechanical properties of CA mortar. As the temperature increase from -40°C to 60°C, its compressive strength decrease from 31.7MPa to 1.5MPa for CRTS I type CA mortar, while the same rule can be found to the flexural strength. Results also showed that as the content of asphalt in mortar increases, the temperature sensitivity of mechanical properties increases.

Abstract: The mechanical and structure designs are carried out in this paper for Sieve-tray tower used in chemical unit operations. Through the use of SW6 soft based on GB150, JB4710,the thickness of the equipment determined and the calculating for load, bending, axial stress are dealt. The strength and stable are checked for every dangerous section. For inner components of tower structure designs are carried out, assembly drawings and parts drawings are given according to the designed results.

Abstract: According to GB151 and GB150, the process design and structure design have been done for the floating head heat exchanger which is common in the chemical unit operation equipment. The software SW6 is used to compute the wall thickness, loading and etc. Strength design and structure design of the Tube-sheets, Tube-Chambers and Supports have also been finished on SW6. The results show that the equipment can meet the required strength.

Abstract: Mounting headstock is an important part of the vegetable transplanting machine, its strength directly affects the machine's performance. The modal analysis of three types of headstocks while lifting and lowering implement were carried out with ANSYS finite element analysis software, the natural vibration characteristics including natural frequency, damping ratio and modal vibration mode of each particular mode without external interference were obtained, The comparison among the three structures was conducted and it may provide a theoretical basis for the structure design of the mounting headstock of vegetable transplanting machine .