scholarly journals Experimental Study on the Flexural Behavior of Reinforced Polystyrene Blocks in Concrete Beams

2021 ◽  
Vol 7 (2) ◽  
pp. 197
Author(s):  
Lim Yong Tat ◽  
Ling Jen Hua ◽  
Lau Ji Wei ◽  
Alicia Yik Yee Min
Keyword(s):  
Weight Ratio ◽  
Point Load ◽  
Load Test ◽  
Flexural Behavior ◽  
Structural Performance ◽  
Construction Costs ◽  
Effective Strength ◽  
New Type ◽  
Successful Reduction ◽  
Better Than

A new type of lightweight beam system was recently proposed by embedding polystyrene in beams to improve structural efficiency. This removes the non-performing concrete in the neutral axis and tension region to provide a comparable strength as a solid beam. There are, however, limited studies conducted to investigate the structural behavior of such beams. Therefore, this research presents an experimental investigation to assess the effect of polystyrene shapes in the beams. This involved testing a solid beam and five lightweight beams under flexural load using a four-point load test. The inclusion of polystyrene was estimated to have reduced the self-weight of beams by 8.6% to 11.8% when compared with the solid beam. The results also showed the ellipse polystyrene with a width of 70 mm and height of 50 mm produced the highest effective strength to weight ratio (sw) of 1.12 and performed 12% better than the solid beam. Moreover, the lightweight beams have more weight reduced than the strength, and those with ellipse polystyrene were found to have performed better than circular ones based on first crack load, ultimate load, and effective strength to weight ratio (sw). The beams with ellipse polystyrene allowed better stress distribution and this gave them a higher strength than sphere shape. For industry application, the polystyrene content is recommended to be greater than 10% while the effective strength to weight ratio (sw) of the beam is greater than 1. The successful reduction of the weight without affecting the structural performance has the ability to help in reducing construction costs.

scholarly journals Performance of Reinforced Concrete Beam with Polystyrene Blocks at Various Regions

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Lim Yong Tat
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Weight Ratio ◽  
Reinforced Concrete Beam ◽  
Point Load ◽  
Load Test ◽  
Rc Beams ◽  
Lightweight Materials ◽  
Point Load Test ◽  
Effective Strength

Lightweight materials, such as polystyrene, can be embedded in reinforced concrete (RC) beams to reduce its weight. However, this may, to some extent, affect the performance of the structure. This research investigates the behaviour of the lightweight beams under load and determines the best position of polystyrene blocks in beams. Nine specimens with a size of 175 mm x 300 mm x 1600 mm were tested under four-point load test. The number and position of polystyrene blocks in the beams were varied. The specimens were evaluated for effectiveness in terms of effective strength to weight ratio (s-w ratio). The lightweight beam was effective when the polystyrene blocks were placed at the neutral and tensile region, offering an s-w ratio of greater than 1. The beam lost 3.8% strength with 8.4% reduction of weight.

Flexural Behavior of Prestressed Concrete Composite Slab with Corrugated Steel Web

2013 ◽  
Vol 351-352 ◽  
pp. 231-236
Author(s):  
He Tao Hou ◽  
Zhong Long Lv ◽  
Hai Ning Liu ◽  
Yan Fei Sun
Keyword(s):  
Finite Element Analysis ◽  
Prestressed Concrete ◽  
Flexural Behavior ◽  
Element Analysis ◽  
Composite Slab ◽  
Bond Slip ◽  
New Type ◽  
Corrugated Steel Web ◽  
Elastic Stage ◽  
Better Than

In order to avoid the failure of bond slip between the new and old concrete of the prestressed concrete composite slab (named PK slab), and the difficulty in the formwork of PK slab, this paper presents a new type of prestressed concrete composite slab with corrugated steel web (named PCCW slab). By using ABAQUS finite element analysis, it was found that the flexural behavior of PCCW slab was better than that of PK slab. Based on the analysis result, it could be seen that at the elastic stage, the flexural strength of PCCW slab increased with the raising of thickness of corrugated steel web, height of concrete flange, width of concrete flange and hole space of corrugated steel web. Among those effects of parameters, the thickness of corrugated steel web and the height of concrete flange were important.

scholarly journals Investigation on flexural behavior of a new-type composite column with steel angles

2020 ◽  
Vol 19 (5) ◽  
pp. 458-479
Author(s):  
Jie Ding ◽  
Yun Zou ◽  
Cheng-Quan Wang ◽  
Hang-Fei Zhou ◽  
Tian-Qi Li
Keyword(s):  
Flexural Behavior ◽  
Composite Column ◽  
New Type ◽  
Steel Angles ◽  
Type Composite

Mechanical and flame retardant properties of isotactic polypropylene/magnesium oxysulfate whisker composite

2017 ◽  
Vol 31 (4) ◽  
pp. 514-534 ◽  
Author(s):  
Li Dang ◽  
Xueying Nai ◽  
Xin Liu ◽  
Donghai Zhu ◽  
Yaping Dong ◽  
...  
Keyword(s):  
Isotactic Polypropylene ◽  
Interfacial Interaction ◽  
Flexural Behavior ◽  
Cone Calorimetry ◽  
Melt Mixing ◽  
Suppression Effect ◽  
Peak Heat Release Rate ◽  
Magnesium Oxysulfate ◽  
Flame Retardant Properties ◽  
Better Than

Isotactic polypropylene (iPP) composites containing magnesium oxysulfate whisker (MOSw) or lauric acid-modified MOSw (LA-MOSw) were prepared via melt mixing in a torque rheometer. Scanning electron microscopy pictures showed that the interface between MOSw and iPP matrix was defined, whereas a vague interface was seen in the iPP–LA-MOSw composites. Mechanical properties of these two groups of composites were investigated in terms of tensile, notched impact, and flexural behavior aspects for the purposes of studying toughening effect of MOSw and LA-MOSw. Tensile results showed that yield strength of composites further reduced with the presence of LA, indicating the decrease in interfacial interaction bewteen iPP matrix and MOSw. As such, LA-MOSw performed better than MOSw in toughening of iPP matrix. Flexural strength and modulus of iPP–MOSw composites increased sharply with the increase in MOSw content, while less dependence on the LA-MOSw content indicated that MOSw was deemed beneficial to increase the stiffness. In addition, flammability properties were investigated by cone calorimetry experiment. The results showed that the peak heat release rate apparently reduced with addition of MOSw or LA-MOSw. Besides, iPP–LA-MOSw composites showed higher specific extinction area values than iPP–MOSw composites, which meant the weaker smoke suppression effect of LA-MOSw. It was chiefly because of the incomplete combustion caused by the continuous and complete charred (MgO) shield. The presence of LA was another possible reason.

scholarly journals Material Considerations in the Microfabrication of Grating Microstructures for use in a Laser-Powered Linear Accelerator

1986 ◽  
Vol 76 ◽  
Author(s):  
John B. Warren
Keyword(s):  
Linear Accelerator ◽  
Material Selection ◽  
Collaborative Work ◽  
Fused Silica ◽  
Image Analyzer ◽  
Metrological Analysis ◽  
Field Gradients ◽  
New Type ◽  
Specialized Form ◽  
Better Than

ABSTRACTCollaborative work between Brookhaven and Los Alamos National Laboratories is developing a new type of linear accelerator that uses a high-power, picosecond pulse CO2 laser to irradiate a specialized form of grating with a pitch of 10.6 microns. The electromagnetic field that results can be used to accelerate electrons at field gradients of several GeV/m with potential efficiencies much better than current accelerators. The grating must be conductive to minimize resistive losses, be able to withstand high fields without damage, and requires dimensional tolerances in the sub-micron range. These requirements focus attention on grating material selection, microfabrication methods, and metrological methods used for quality control. At present, several types of gratings have been manufactured by reactive ion etching of fused silica in CHF 3/Ar or etching silicon with KOH/H 2O or ethylenediamine-pyrocatechol solutions. Metrological analysis of the gratings has begun with a Tracor Northern 5700 digital image analyzer.

Development of a new class of precast concrete pipes - an experimental evaluation

2007 ◽  
Vol 34 (7) ◽  
pp. 885-889 ◽  
Author(s):  
H El Naggar ◽  
E N Allouche ◽  
M H. El Naggar
Keyword(s):  
Experimental Evaluation ◽  
Solid Wall ◽  
Research Effort ◽  
Precast Concrete ◽  
Load Test ◽  
Added Value ◽  
Structural Performance ◽  
Concrete Pipes ◽  
Concrete Pipe ◽  
Cellular Concrete

Concrete pipes represent the backbone of the municipal storm and wastewater collection systems of Ontario, Canada. Industry and academia partnered on a research effort that aimed at developing new precast-concrete pipe products that provide added value to the final user in comparison with existing products. This paper describes a full-scale experimental evaluation of the design, manufacturing, and performance aspects of a "cellular" concrete pipe, a precast concrete pipe in which multiple continuous conduits were incorporated within its wall. Two fully-instrumented prototype segments of the proposed cellular concrete pipe were manufactured using standard dry-cast manufacturing procedures. The pipe segments were subjected to a D-load test to evaluate their structural performance. The observed structural performance was found to be comparable to solid-wall specimens, particularly when a four-conduit configuration was used. Of the six materials used as conduits, PVC and aluminum were found to perform the best. The presence of the conduits appears to delay the on-set of major cracks, thus increasing the D-load value. Key words: precast, concrete, pipe, experimental, conduit system, trenchless construction methods.

scholarly journals Point Load Test of Half-Cylinder Core Using the Numerical Model and Laboratory Tests: Size Suggestion and Correlation with Cylinder Core

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Fengyu Ren ◽  
Huan Liu ◽  
Rongxing He ◽  
Guanghui Li ◽  
Yang Liu
Keyword(s):  
Numerical Model ◽  
Laboratory Tests ◽  
Failure Load ◽  
Field Tests ◽  
Point Load ◽  
Diameter Ratio ◽  
Load Test ◽  
Index Test ◽  
Point Load Test ◽  
Calculation Procedures

The point load test (PLT) is intended as an index test for rock strength classification or estimations of other strength parameters because it is economical and simple to conduct in the laboratory and in field tests. In the literature, calculation procedures for cylinder cores, blocks, or irregular lumps can be found, but no study has researched such procedures for half-cylinder cores. This paper presents the numerical model and laboratory tests for half-cylinder and cylinder specimens. The results for half-cylinder and cylinder specimens are then presented, analysed, and discussed. A correlation of failure load between half-cylinder and cylinder specimens is established with a suitable size suggestion and correction factor. It is found that the failure load becomes stable when half-cylinder specimens have a length/diameter ratio higher than 0.9. In addition, the results show that the point load strength index (PLSI) of half-cylinder cores can be calculated using the calculation procedures for diametral testing on cylinder cores, and it is necessary to satisfy the conditions that the length/diameter ratio be higher than 0.9 and the failure load be multiplied by 0.8.

Relation of blood-free to blood-inclusive postmortem lung water measurements in sheep

1985 ◽  
Vol 59 (2) ◽  
pp. 592-596 ◽  
Author(s):  
J. C. Collins ◽  
J. H. Newman ◽  
N. E. Wickersham ◽  
W. K. Vaughn ◽  
J. R. Snapper ◽  
...  
Keyword(s):  
Extravascular Lung Water ◽  
Weight Ratio ◽  
Lung Homogenate ◽  
Lung Water ◽  
Before And After ◽  
The Mean ◽  
Space Expansion ◽  
Highly Correlated ◽  
Linear Regressions ◽  
Better Than

Our purpose was to see if the postmortem weight ratio of extravascular lung water to blood-free dry lung (blood-free ratio) was related to similar ratios in blood-inclusive lung and in blood. We developed linear regressions of blood-free ratio on ratios for blood-inclusive lung and blood together and for blood-inclusive lung alone for 73 sheep studied under 11 different protocols and for two subgroups of sheep, one with plasma space expansion and the other without expansion. The relation of ratios of blood-free to blood-inclusive lungs was different between the two subgroups. Although all regressions were highly correlated, the fits of the blood-free ratio on ratios for blood-inclusive lung and blood together were better than for blood-inclusive lung alone. The mean error of prediction of extravascular lung water for all sheep was significantly less for the regression of blood-free ratio on ratios for blood and blood-inclusive lung together (11 g) than for blood-inclusive lung alone (18 g). This study shows that weights of lung homogenate and blood samples before and after simple oven drying can be used to provide accurate inexpensive estimates of postmortem extravascular lung water.

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