Research Flexural Properties of Prestressed Slabs

2015 ◽  
Vol 727-728 ◽  
pp. 417-420
Author(s):  
Xian Hong Meng ◽  
Lin Tong
Keyword(s):  
Mechanical Properties ◽  
Flexural Properties ◽  
Maximum Deflection ◽  
Composite Slab ◽  
Flexural Performance ◽  
Distributed Load ◽  
Under Construction ◽  
Construction Loads ◽  
Plate Deflection

This paper is aimed to study on the flexural performance of prestressed slab and prestressed composite slab ,in order to provide the reference in engineering.At first,the prestressed slab is loaded under unformly distributed load,and then prestressed plate deflection , crack measurements. According to the phenomenon and data of the test, the mechanical properties of prestressed slab is analyzed. The maximum deflection of prestressed slab satisfy the standard requirements under construction loads.

scholarly journals Flexural Properties of PVC/Bamboo Composites under Static and Dynamic-Thermal Conditions: Effects of Composition and Water Absorption

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Shahril Anuar Bahari ◽  
Warren J. Grigsby ◽  
Andreas Krause
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Dynamic Mechanical Thermal Analysis ◽  
Elevated Temperatures ◽  
Flexural Modulus ◽  
Thermal Conditions ◽  
Flexural Properties ◽  
Particle Sizes ◽  
Flexural Performance

Polyvinyl chloride (PVC)/bamboo composites have been prepared and assessed for their use in interior and exterior load-bearing applications. PVC composites were formed by compounding PVC with different bamboo particle sizes and loadings. The mechanical properties of these composites were determined at both ambient and elevated temperatures and after long-term water soaking. Analysis revealed that bamboo incorporation improved the PVC composite flexural modulus which was also observed with dynamic mechanical-thermal analysis on heating composites toca.70°C. Addition of 25% and 50% bamboo particles increases flexural modulus by 80% with dependency on whether fine (<75 μm) or coarse (<1 mm) particles were used. On water soaking to saturation, composites had water weight uptakes of 10%, with reduced flexural properties obtained for all water-soaked composites. Nonetheless, the results of this study show that PVC/bamboo composites achieve the minimum flexural performance of ASTM D 6662, indicating potential for their use in exterior applications.

Mechanical Property Studies on Flax Fiber Reinforced Basalt Powder Filled Polyester Composite

2020 ◽  
Vol 13 ◽  
Author(s):  
V. Arumugaprabu ◽  
K.Arun Prasath ◽  
S. Mangaleswaran ◽  
M. Manikanda Raja ◽  
R. Jegan
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Natural Fiber ◽  
Tensile Load ◽  
Flax Fiber ◽  
Flexural Properties ◽  
Weight Percentage ◽  
Tensile Impact ◽  
Polyester Composite ◽  
Additional Support

: The objective of this research is to evaluate the tensile, impact and flexural properties of flax fiber and basalt powder filled polyester composite. Flax fiber is one of the predominant reinforcement natural fiber which possess good mechanical properties and addition of basalt powder as a filler provides additional support to the composite. The Composites are prepared using flax fiber arranged in 10 layers with varying weight percentage of the basalt powder as 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.% and 30 wt.% respectively. From the results it is inferred that the composite combination 10 Layers of flax / 5 wt.%, basalt Powder absorbs more tensile load of 145 MPa. Also, for the same combination maximum flexural strength is about 60 MPa. Interestingly in the case of impact strength more energy was absorbed by 10 layers of flax and 30 wt.% of basalt powder. In addition, the failure mechanism of the composites also discussed briefly using SEM studies.

Monitoring of mechanical properties of prestressed glass fiber epoxy composites over 12 months after fabrication

2021 ◽  
pp. 002199832110047
Author(s):  
Mahmoud Mohamed ◽  
Siddhartha Brahma ◽  
Haibin Ning ◽  
Selvum Pillay
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Flexural Strength ◽  
Compressive Residual Stress ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Epoxy Composites ◽  
Flexural Properties ◽  
Initial Increase ◽  
Fiber Volume

Fiber prestressing during matrix curing can significantly improve the mechanical properties of fiber-reinforced polymer composites. One primary reason behind this improvement is the generated compressive residual stress within the cured matrix, which impedes cracks initiation and propagation. However, the prestressing force might diminish progressively with time due to the creep of the compressed matrix and the relaxation of the tensioned fiber. As a result, the initial compressive residual stress and the acquired improvement in mechanical properties are prone to decline over time. Therefore, it is necessary to evaluate the mechanical properties of the prestressed composites as time proceeds. This study monitors the change in the tensile and flexural properties of unidirectional prestressed glass fiber reinforced epoxy composites over a period of 12 months after manufacturing. The composites were prepared using three different fiber volume fractions 25%, 30%, and 40%. The results of mechanical testing showed that the prestressed composites acquired an initial increase up to 29% in the tensile properties and up to 32% in the flexural properties compared to the non-prestressed counterparts. Throughout the 12 months of study, the initial increase in both tensile and flexural strength showed a progressive reduction. The loss ratio of the initial increase was observed to be inversely proportional to the fiber volume fraction. For the prestressed composites fabricated with 25%, 30%, and 40% fiber volume fraction, the initial increase in tensile and flexural strength dropped by 29%, 25%, and 17%, respectively and by 34%, 26%, and 21%, respectively at the end of the study. Approximately 50% of the total loss took place over the first month after the manufacture, while after the sixth month, the reduction in mechanical properties became insignificant. Tensile modulus started to show a very slight reduction after the fourth/sixth month, while the flexural modulus reduction was observed from the beginning. Although the prestressed composites displayed time-dependent losses, their long-term mechanical properties still outperformed the non-prestressed counterparts.

Pore Structure and Mechanical Properties of ZrC/SiC Multi-Components Modified C/C Composites

2013 ◽  
Vol 833 ◽  
pp. 159-164 ◽  
Author(s):  
Xiu Qian Li ◽  
Hai Peng Qiu ◽  
Jian Jiao
Keyword(s):  
Mechanical Properties ◽  
Pore Diameter ◽  
Testing Machine ◽  
Average Pore Diameter ◽  
Flexural Properties ◽  
Matrix Interface ◽  
Polymeric Precursor ◽  
Average Pore ◽  
Fiber Matrix Interface ◽  
Injection Apparatus

The ZrC/SiC multi-components modified C/C composites were prepared by using a hybrid precursor containning polycarbosilane and organic zirconium-contained polymeric precursor as impregnant and C/C composites of low density as preform. The porosity, microstructure and mechanical properties of samples were characterized with mercury injection apparatus, scanning electron microscopy and universal electron testing machine respectively. The results show that the porosity and average pore diameter decrease firstly and increase subsequently with the increase of organic zirconium content of the precursor. When the content of organic zirconium is 50%, the porosity and average pore diameter reach minimum which were7.27% and 0.0795um respectively. The most probabilistic pore diameter shifted from 10-100um to 1-10um at the same time; Meanwhile, the flexural properties also increases and drops immediately as the content of organic zirconium in the precursor adds. When the content of organic zirconium is 25%, the flexural strength reaches maximum of 245.20MPa.The improved flexural properties is attributed to the proper bonding of fiber-matrix interface and the low porosity of samples.

scholarly journals Flexural Behavior of Extruded DFRCC Panel and Reinforced Concrete Composite Slab

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Chang-Geun Cho ◽  
Bang Yeon Lee ◽  
Yun Yong Kim ◽  
Byung-Chan Han ◽  
Seung-Jung Lee
Keyword(s):  
Reinforced Concrete ◽  
Cement Composite ◽  
Extrusion Process ◽  
Flexural Behavior ◽  
Composite Slab ◽  
Flexural Performance ◽  
Cracking Control ◽  
Rc Slab ◽  
Reinforced Cement ◽  
Deformation Hardening

This paper presents a new reinforced concrete (RC) composite slab system by applying an extruded Ductile Fiber Reinforced Cement Composite (DFRCC) panel. In the proposed composite slab system, the DFRCC panel, which has ribs to allow for complete composite action, is manufactured by extrusion process; then, the longitudinal and transverse reinforcements, both at the bottom and the top, are placed, and finally the topping concrete is placed. In order to investigate the flexural behavior of the proposed composite slab system, a series of bending tests was performed. From the test results, it was found that the extruded DFRCC panel has good deformation-hardening behavior under flexural loading conditions and that the developed composite slab system, applied with an extruded DFRCC panel, exhibits higher flexural performance compared to conventional RC slab system in terms of the stiffness, load-bearing capacity, ductility, and cracking control.

The effect of organofluorine additives on the morphology, thermal conductivity and mechanical properties of rigid polyurethane and polyisocyanurate foams

2021 ◽  
pp. 0021955X2098715
Author(s):  
Cosimo Brondi ◽  
Ernesto Di Maio ◽  
Luigi Bertucelli ◽  
Vanni Parenti ◽  
Thomas Mosciatti
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Cell Size ◽  
Flexural Properties ◽  
Anisotropy Ratio ◽  
Cell Content ◽  
Average Cell Size ◽  
Average Cell ◽  
Thermal Insulating ◽  
Liquid Type

This study investigates the effect of liquid-type organofluorine additives (OFAs) on the morphology, thermal conductivity and mechanical properties of rigid polyurethane (PU) and polyisocyanurate (PIR) foams. Foams were characterized in terms of their morphology (density, average cell size, anisotropy ratio, open cell content), thermal conductivity and compressive as well as flexural properties. Based on the results, we observed that OFAs efficiently reduced the average cell size of both PU and PIR foams, leading to improved thermal insulating and mechanical properties.

One Vanderbilt: Unprecedented Project Delivery Through Integrated Innovation

2019 ◽  
Author(s):  
Andrew Cleary ◽  
Edward M. DePaola ◽  
Christopher R. Horch
Keyword(s):  
New York ◽  
Structural Steel ◽  
Fast Track ◽  
Urban Environments ◽  
Advanced Technology ◽  
Parametric Modelling ◽  
Under Construction ◽  
Construction Loads ◽  
Design Schedule ◽  
Construction Documents

<p>One Vanderbilt Avenue, currently under construction in midtown Manhattan, will be one of the tallest buildings in New York. By collaborating with the construction teams in the early stages of the design, the foundations and the superstructure were able to proceed well in advance of a typical project. For example, the structural steel was erected to the 6th floor, was fabricated to the 32nd Floor, and the shop drawings were checked up to the 45th floor on the day that the 100% Construction Documents were issued.</p><p>The structural steel frame was designed so that its core columns only carried 12 levels of framing and construction loads during the tower’s erection. A concrete shear wall system followed the steel framing, permitting the steel erection to proceed without regard to the concrete operations. When complete, the project will stand 1,401 feet tall and contain 26,000 tons of structural steel, and 93,000 cubic yards of concrete.</p><p>The presentation focuses on the challenges and technological requirements for vertical construction in dense urban environments. It explains the amount of detail, thought, and knowledge of construction that must happen earlier in the design process and the participants will appreciate how the fast‐track process can be applied to complex architectural, mechanical and structural designs.</p><p>It describes the integration of design team parametric modelling with the construction process early in the design schedule. Fast‐track projects with complex designs like One Vanderbilt can be successfully completed by understanding and integrating an IPD process, even with competing objectives. The presentation discusses the challenges and technological requirements for vertical construction in dense urban environments, including the importance of direct links to mass transportation.</p><p>This type of team structure is the future of the industry, and One Vanderbilt is the first of its kind to illustrate how innovative design ambitions are being realized through the use of increasingly refined and advanced technology.</p>

Co-milling-assisted exfoliated graphite nanoplatelets filler introduction in polyethylene and alumina composites

2018 ◽  
Vol 53 (13) ◽  
pp. 1815-1826
Author(s):  
Sheng Cai Tan ◽  
Jimmy KW Chan ◽  
Kian Ping Loh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Materials ◽  
Exfoliated Graphite ◽  
Flexural Properties ◽  
Graphite Nanoplatelets ◽  
Alumina Composites ◽  
Exfoliated Graphite Nanoplatelets ◽  
Polyethylene Composites

This paper aims to investigate the effect of co-milling-assisted exfoliation of graphite into polyethylene and alumina matrices on the mechanical properties of the composites. Tensile mechanical properties of composite materials based on polyethylene reinforced with graphite and graphite-derived fillers at 0–0.75 wt% loading were investigated, while hardness and flexural properties of alumina composites with 0.25 wt% loading of the same additives were assessed. Exfoliated graphite, applied at 0.25–0.75 wt% in pre-exfoliated form or in a co-milling-assisted fashion, has been demonstrated to be effective in enhancing the tensile strength of polyethylene composites. Similar enhancement in hardness and flexural properties was observed in alumina composites with 0.25 wt% loading of the exfoliated graphite. Co-milling-assisted exfoliated graphite nanoplatelets additive introduction has been found to effect a more desirable mechanical properties enhancement in the composites investigated in this study.

The Effect of Fiber Size on the Mechanical Properties of Bertam/Unsaturated Polyester Composites

2015 ◽  
Vol 761 ◽  
pp. 52-56
Author(s):  
M.H. Norhidayah ◽  
Arep Hambali ◽  
M.Y. Yuhazri
Keyword(s):  
Mechanical Properties ◽  
Fiber Length ◽  
Unsaturated Polyester ◽  
Flexural Modulus ◽  
Flexural Properties ◽  
Fiber Size ◽  
Polyester Composites

The aim of this paper was the effects of different fiber size on tensile and flexural properties. Preparation of thermoset unsaturated polyester reinforced with particle Bertam (Eugeissona tristis) was done by hand layout method. Bertam/polyester composites containing Bertam fiber of different sizes, i.e., 15, 120 and 284 μm were prepared. For each composite, eight specimens were tested to evaluate the mechanical properties. It was found that composite reinforced with Bertam having the shortest fiber length, i.e, 15 μm showed the highest tensile and flexural modulus, which were 204.14 MPa and 1826.78 MPa, respectively.

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