Experiment on the Bending Performance of Sea Sand Concrete Beam under the Artificial Climate Environment

2011 ◽  
Vol 217-218 ◽  
pp. 1380-1384
Author(s):  
Heng Lin Lv ◽  
Ya Lin Song ◽  
Yan Li
Keyword(s):  
Indoor Environment ◽  
Concrete Beam ◽  
Mechanical Performance ◽  
Great Influence ◽  
Chloride Ion ◽  
Climate Conditions ◽  
Bending Performance ◽  
Sea Sand ◽  
Desalination Technology ◽  
Load Deflection Curve

Through the experiment on the durability of sea sand concrete beam which is subject to climate conditions and indoor environment, the change of deflection, beam load-deflection curve, ductility and crack are studied. The results show: concrete beams that are mixed with sea sand are deteriorated by the chloride ion and their load-deflection curves as well as stiffness and ductility are reduced in different degree. But other beams that are mixed with desalinated sea sand are reduced not obviously. Otherwise, because of the bad environment accelerating degradation of the component mechanical performance and the sea sand desalination technology increasing the ability to resist environmental erosion, the component mechanical performance and the sea sand desalination technology take great influence to the component mechanical performance.

Experiment on Bending Performance of Double Mixing HPC Concrete Beam under the Artificial Climate Environment

2011 ◽  
Vol 217-218 ◽  
pp. 1385-1391
Author(s):  
Heng Lin Lv ◽  
Ji Qian ◽  
Yong Sheng Yi ◽  
Yan Li ◽  
Xiao Wen Zhu
Keyword(s):  
Natural Environment ◽  
Concrete Beam ◽  
Deflection Curve ◽  
Climate Conditions ◽  
Bending Performance ◽  
Ordinary Concrete ◽  
Service State ◽  
Load Deflection Curve

Through the experiment on HPC beam which is subject to artificial climate conditions and indoor natural environment, section strain, beam load-deflection curve, failure and cracks are studied. The results show: compared with ordinary concrete beam, the HPC beam which has been subject to artificial climate conditions has higher stiffness; the deflection amount and the width of crack of this concrete beam all fall in the confines of ultimate service state under use load; and the beam displays a better ductility in failure

scholarly journals Agrometeorological models for estimating sweet cassava yield

2018 ◽  
Vol 48 (1) ◽  
pp. 43-51
Author(s):  
Victor Brunini Moreto ◽  
Lucas Eduardo de Oliveira Aparecido ◽  
Glauco de Souza Rolim ◽  
José Reinaldo da Silva Cabral de Moraes
Keyword(s):  
Great Influence ◽  
Soil Water Storage ◽  
Percentage Error ◽  
P Value ◽  
Climate Conditions ◽  
Paulo State ◽  
State Water ◽  
The Mean ◽  
Sweet Cassava ◽  
Main Factor

ABSTRACT Brazil is the fourth largest producer of cassava in the world, with climate conditions being the main factor regulating its production. This study aimed to develop agrometeorological models to estimate the sweet cassava yield for the São Paulo state, as well as to identify which climatic variables have more influence on yield. The models were built with multiple linear regression and classified by the following statistical indexes: lower mean absolute percentage error, higher adjusted determination coefficient and significance (p-value < 0.05). It was observed that the mean air temperature has a great influence on the sweet cassava yield during the whole cycle for all regions in the state. Water deficit and soil water storage were the most influential variables at the beginning and final stages. The models accuracy ranged in 3.11 %, 6.40 %, 6.77 % and 7.15 %, respectively for Registro, Mogi Mirim, Assis and Jaboticabal.

Test and Study on Green High-Performance Marine Concrete Containing Ultra-Fine Limestone Powder

2013 ◽  
Vol 368-370 ◽  
pp. 1112-1117
Author(s):  
Jin Hui Li ◽  
Liu Qing Tu ◽  
Ke Xin Liu ◽  
Yun Pang Jiao ◽  
Ming Qing Qin
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Mechanical Performance ◽  
Chloride Ion ◽  
Limestone Powder ◽  
Ion Permeability ◽  
High Quality ◽  
Cracking Resistance ◽  
Slag Powder ◽  
Marine Concrete

In order to solve the environment pollution of limestone powder during production of limestone manufactured sand and gravel and problem of lack of high quality fly ash or slag powder in ocean engineering, ultra-fine limestone powder was selected for preparation of green high-performance marine concrete containing fly ash and limestone powder and that containing slag powder and limestone powder for tests on workability, mechanical performance, thermal performance, shrinkage, and resistance to cracking and chloride ion permeability. And comparison was made between such green high-performance concrete and conventional marine concrete containing fly ash and slag powder. Moreover, the mechanism of green high-performance marine concrete was preliminary studied. Results showed that ultra-fine limestone powder with average particle size around 10μm had significant water reducing function and could improve early strength of concrete. C50 high-performance marine concrete prepared with 30% fly ash and 20% limestone powder or with 30% slag powder and 30% limestone powder required water less than 130kg/m3, and showed excellent workability with 28d compressive strength above 60MPa, 56d dry shrinkage rate below 300με, cracking resistance of grade V, 56d chloride ion diffusion coefficient not exceeding 2.5×10-12m2/s. Mechanical performance and resistance to chloride ion permeability of limestone powder marine concrete were quite equivalent to those of conventional marine concrete. But it had better workability, volume stability and cracking resistance. Moreover, it can serve as a solution to the lack of high quality fly ash and slag powder.

Effects of Intensity of Alternating Electromagnetic Field on Microstructure and Property of ZL114A Aluminum Alloy Castings

2013 ◽  
Vol 278-280 ◽  
pp. 429-432
Author(s):  
Qing Song Yan ◽  
Yong Li ◽  
Gang Lu ◽  
Bai Ping Lu ◽  
Bo Wen Xiong ◽  
...  
Keyword(s):  
Grain Size ◽  
Electromagnetic Field ◽  
Aluminum Alloy ◽  
Mechanical Performance ◽  
Great Influence ◽  
Current Intensity ◽  
Alloy Castings

Through analyzing and testing the microstructure and property of ZL114A aluminum alloy castings under the condition of alternating electromagnetic field, the effects of the intensity of alternating electromagnetic field on the microstructure and property of ZL114A aluminum alloy castings are studied. The results showed the intensity of alternating electromagnetic field had a great influence on the microstructure and property of ZL114A aluminum alloy castings. With the increase of the intensity of alternating electromagnetic field, the grain size of ZL114A aluminum alloy was more and more small, under the 10A current intensity, the grain was the finest. Whereas, with the increase of the intensity of alternating electromagnetic field further, the grain is more and more big. Meanwhile, in a certain rang of current intensity, the mechanical performance of ZL114A aluminum alloy had been improved comprehensively, its tensile intensity was improved 10MPa and the elongation was increased by 30%.

scholarly journals The Influence of the Hybridization of Steel and Polyolefin Fiber on the Mechanical Properties of Base Concrete Designed for Marine Shotcreting Purposes

2021 ◽  
Vol 11 (20) ◽  
pp. 9456
Author(s):  
Changjoon Lee ◽  
Andres Salas Montoya ◽  
Hoon Moon ◽  
Hyunwook Kim ◽  
Chulwoo Chung
Keyword(s):  
Steel Fiber ◽  
Mechanical Performance ◽  
Synergetic Effect ◽  
Chloride Ion ◽  
Concrete Specimen ◽  
Hybrid Fiber ◽  
Electrically Conductive ◽  
Chloride Ion Penetration ◽  
Binder Ratio ◽  
Ion Penetration

The present study investigated the influence of the hybridization of steel and polyolefin fiber on the mechanical performance and chloride ion penetration of base concrete designed for marine shotcreting purposes. The purpose of fiber hybridization is to reduce the risk of corrosion that might occur during service life. Sets of hybrid fiber reinforced base concrete, whose water to binder ratio was 0.338, were prepared. The fiber contents in the base concrete were 0.54 and 1.08 vol%, and the volume proportion of polyolefin fiber in the hybrid fiber varied from 0 to 100%. Although the effect of fiber hybridization was not clearly observed from the compressive strength, a synergetic effect which increased both the flexural strength and toughness occurred at a fiber content of 1.08 vol%. The optimum ratio of steel and polyolefin fiber was 50:50. With respect to chloride ion penetration, an increasing amount of steel fiber increased the amount of current passing through the base concrete specimen due to the presence of electrically conductive steel fiber. However, chloride ion diffusivity was not greatly affected by the presence of steel fiber.

Experimental Study on Flexural Performances of Concrete Beams Strengthened with Near-Surface Mounted (NSM) FRP Reinforcement

2010 ◽  
Vol 163-167 ◽  
pp. 3634-3639
Author(s):  
Li Li Sui ◽  
Tie Jun Liu ◽  
Feng Xing ◽  
Yu Xiang Fu
Keyword(s):  
Experimental Study ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Flexural Stiffness ◽  
Test Results ◽  
Near Surface ◽  
Bending Performance ◽  
Bending Capacity ◽  
Frp Reinforcement ◽  
Near Surface Mounted

This paper illustrates the results of an experimental study on the bending performance of concrete beams strengthened with near-surface mounted (NSM) FRP reinforcement. The critical parameter of the embedded length of NSM-FRP plates was investigated in particularly. The test results indicated that NSM-FRP reinforcement can significantly improve the strength and crack resistance capacity of the concrete beam, reducing the size of cracks. The embedded length of the NSM-FRP plate has distinct influence on the cracking and bending capacity, the flexural stiffness, and the crack developments of the concrete beam. As the embedded length increased, the bending capacity and the flexural stiffness increased correspondingly and the crack developed more intensively.

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