scholarly journals Structural Behavior of Lightweight Composite Slab System

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
Nur Adidah Sutiman ◽  
◽  
Masni A. Majid ◽  
Zainorizuan Mohd Jaini ◽  
Aina Syafawati Roslan ◽  
...  
Keyword(s):  
Steel Sheet ◽  
Ultimate Load ◽  
Major Effect ◽  
Structural Behavior ◽  
Minor Effect ◽  
Composite Slab ◽  
Four Point Bending ◽  
Point Test ◽  
Foamed Concrete ◽  
Infill Material

This study investigate the structural behavior of lightweight composite slab system that consist of profiled steel sheet (PSS) attached to dry board (DB) using mechanical screws and with or without infill materials. A total four full-scale panel specimen were tested under four-point bending when subjected under static loading. Result of the four-point test shows that increasing the thickness of profiles steel sheet gives major effect to the deflection and ultimate load. The deflection and ultimate load of 1.0mm thick panel specimen is 16.45% and 34.45% respectively. Therefore, increased the thickness of profiled steel sheet can enhance the stiffness and strength of the lightweight composite slab systems. It also found that the infill material used in these experimental gives minor effect to deflection and ultimate load. The deflection and ultimate load of panel specimen with foamed concrete is 21.18% and 16.66% respectively. Thus, foamed concrete can be used only for non-structural purposed only such as sound proofing and fire resistance.

Structural Design of High-Performance Concrete Bridge Beams

2000 ◽  
Vol 1696 (1) ◽  
pp. 171-178
Author(s):  
Xiaoming (Sharon) Huo ◽  
Maher K. Tadros
Keyword(s):  
Structural Design ◽  
High Performance ◽  
High Performance Concrete ◽  
Highway Bridges ◽  
Major Effect ◽  
Minor Effect ◽  
Bottom Flange ◽  
Prestress Losses ◽  
Bridge Beams ◽  
Creep And Shrinkage

Recently high-performance concrete (HPC) has been used in highway bridges and has gained popularity for its short-term and prospective long-term performances. Benefits of using HPC include fewer girder lines required, longer span capacity of girders, reduced creep and shrinkage deformation, less prestress losses, longer life cycle, and less maintenance of bridges. Research has been conducted on several issues of structural design of HPC bridge beams. The topics discussed include the effects of section properties of prestressed concrete girders, allowable tensile and compressive stresses, creep and shrinkage deformations of HPC, and prediction of prestress losses with HPC. The results from a parametric study have shown that a section that can have a large number of strands placed in its bottom flange is more suitable for HPC applications. The use of 15-mm-diameter prestressing strands allows the higher prestressing force applied on sections and can provide more efficiency in HPC bridges. The research results also indicate that the allowable compressive strength of HPC has a major effect on the structural design of bridges, whereas the allowable tensile stress has a minor effect on the design. Equations for predicting prestress losses based on the experimental and analytical results are recommended. The recommended equations consider the effects of lower creep and shrinkage deformations of HPC.

PERFORMANCE OF CONNECTED PRECAST LIGHTWEIGHT SANDWICH FOAMED CONCRETE PANEL UNDER FLEXURAL LOAD

2015 ◽  
Vol 75 (9) ◽  
Author(s):  
Noridah Mohamad ◽  
Abdul Aziz Abdul Samad ◽  
Noorwirdawati Ali ◽  
Josef Hadipramana ◽  
Norwati Jamaluddin
Keyword(s):  
Failure Modes ◽  
Ultimate Load ◽  
Core Layer ◽  
Crack Pattern ◽  
Control Panel ◽  
Structural Behaviour ◽  
The Core ◽  
Steel Bar ◽  
Mode Of Failure ◽  
Foamed Concrete

This paper investigates the structural behaviour of two connected Sandwiched Precast Lightweight Foamed Concrete Panel (PLFP) in term of their load bearing capacities and failure modes. Three (3) connected PLFP panels were cast using foamed concrete as the wythe and polystyrene as the core layer. Each connected panel were cast from two single panels connected using L-bar connection. The panels were strengthened with steel bar reinforcement embedded in both wythes which were connected to each other by the steel shear truss connectors. The connected PLFP panels were tested under flexural load. A single PLFP panel was cast as a control panel and tested under axial load. The results were analysed in term of the panel’s ultimate load, crack pattern and mode of failure. Results showed that the two connected PLFP panels were able to sustain slightly lower ultimate load compared to single PLFP panel. Crack at 45 degree angle at top half of panel and small crack at surface between joint of the connection were observed.

Structural Behaviour of Precast Lightweight Foamed Concrete Sandwich Panel (PLFP) with Double Shear Truss Connectors under Axial Load: Preliminary Result

2013 ◽  
Vol 795 ◽  
pp. 190-194
Author(s):  
S. Samsuddin ◽  
I. Ahmad ◽  
W.I. Goh ◽  
N. Mohamad ◽  
Abdul Aziz Abdul Samad ◽  
...  
Keyword(s):  
Experimental Data ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Axial Loading ◽  
Load Carrying Capacity ◽  
Structural Behaviour ◽  
Double Shear ◽  
Load Carrying ◽  
Foamed Concrete ◽  
Ultimate Load Carrying Capacity

This report provides experimental data on the development of PLFP for building construction. An innovative concept was used in the design of this system and the use of lightweight foamed concrete was discussed. Preliminary result of PLFP with double shear truss connectors was analysed and presented. PLFP was tested to determine its ultimate load carrying capacity under axial loading. Ultimate load carrying capacity, load deflection profile, surface strains and crack pattern were recorded and analysed. Test results were compared with calculated values based on classical formulas that developed by previous researchers and experimental data from previous researchers on its compositeness in between wythes. Results shown that PLFP with double shear truss connectors achieved higher compositeness in between wythes and have adequate ultimate load carrying capacity.

scholarly journals A New Composite Slab Using Crushed Waste Tires as Fine Aggregate in Self-Compacting Lightweight Aggregate Concrete

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2551 ◽  
Author(s):  
Jing Lv ◽  
Tianhua Zhou ◽  
Hanheng Wu ◽  
Liurui Sang ◽  
Zuoqian He ◽  
...  
Keyword(s):  
Ultimate Load ◽  
Bending Moment ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Flexural Properties ◽  
Aggregate Concrete ◽  
Composite Slab ◽  
Yield Load ◽  
Composite Slabs ◽  
Rubber Particles

A composite slab comprised of self-compacting rubber lightweight aggregate concrete (SCRLC) and profiled steel sheeting is a new type of structural element with a series of superior properties. This paper presents an experimental research and finite element analysis (FEA) of the flexural behavior of composite slabs consisting of SCRLC to develop a new floor system. Four composite slabs specimens with different shear spans (450 mm and 800 mm) and SCRLC (0% and 30% in rubber particles substitution ratio) are prepared, and the flexural properties including failure modes, deflection at mid-span, profiled steel sheeting, and concrete surface stain at mid-span and end slippage are investigated by four-point bending tests. The experimental results indicate that applying SCRLC30 in composites slabs will improve the anti-cracking ability under the loading of composite slabs compared with composite slabs consisting of self-compacting lightweight aggregate concrete (SCLC). FEM on the flexural properties of SCRLC composites slabs show that the yield load, ultimate load, and deflection corresponding to the yield load and the ultimate load of composite slabs drop as the rubber particles content increases in SCRLC. The variation of SCRLC strength has less impact on the flexural bearing capacity of corresponding composite slabs. Based on the traditional calculated method of the ultimate bending moment of normal concrete (NC) composite slabs, a modified calculated method for the ultimate bending moment of SCRLC composite slabs is proposed.

scholarly journals Hydrocarbon fluxes above a Scots pine forest canopy: measurements and modeling

2007 ◽  
Vol 7 (12) ◽  
pp. 3361-3372 ◽  
Author(s):  
J. Rinne ◽  
R. Taipale ◽  
T. Markkanen ◽  
T. M. Ruuskanen ◽  
H. Hellén ◽  
...  
Keyword(s):  
Scots Pine ◽  
Forest Canopy ◽  
Transport Model ◽  
Proton Transfer Reaction ◽  
Major Effect ◽  
Systematic Difference ◽  
Chemical Degradation ◽  
Research Station ◽  
Minor Effect ◽  
A Minor

Abstract. We measured the fluxes of several hydrocarbon species above a Scots pine (Pinus sylvestris) stand using disjunct eddy covariance technique with proton transfer reaction – mass spectrometry. The measurements were conducted during four days in July at SMEAR II research station in Hyytiälä, Finland. Compounds which showed significant emission fluxes were methanol, acetaldehyde, acetone, and monoterpenes. A stochastic Lagrangian transport model with simple chemical degradation was applied to assess the sensitivity of the above canopy fluxes to chemistry. According to the model, the chemical degradation had a minor effect on the fluxes measured in this study but may have a major effect on the vertical flux profiles of more reactive compounds, such as sesquiterpenes. The monoterpene fluxes derived using M81 and M137 had a systematic difference with the latter one being higher. These fluxes followed the traditional exponential temperature dependent emission algorithm but were considerably higher than the fluxes measured before at the same site. The normalized monoterpene emission potentials at 30°C, obtained using the temperature dependence coefficient of 0.09°C−1, were 2.0 μg gdw−1 h−1 and 2.5 μg gdw−1 h−1, for fluxes derived using M81 and M137.

Physiological and Ecological Significance of the Chemical Instability of Uric Acid and Related Purines in Sea Water and Marine Algal Culture Medium

1974 ◽  
Vol 31 (8) ◽  
pp. 1327-1335 ◽  
Author(s):  
Naval J. Antia ◽  
Arthur F. Landymore
Keyword(s):  
Uric Acid ◽  
Culture Medium ◽  
Sea Water ◽  
Major Effect ◽  
Small Degree ◽  
Algal Culture ◽  
Minor Effect ◽  
Chemical Instability ◽  
Concentration Changes ◽  
Marine Algal

The chemical instability of uric acid and related purine bases in a seawater phytoplankton culture medium was evaluated spectrophotometrically from concentration changes incurred on aseptic incubation at about 20 C under cool-white light or complete darkness. Uric acid showed slow degradation in darkness, which was increased severalfold by illumination. Xanthine showed a small degree of degradation only from illumination, but adenine, guanine, and hypoxanthine appeared to be stable under both test conditions. The degradation of uric acid was traced to three factors differing in intensity of effect: 1) pH of sea water (minor effect), 2) photolysis (additional minor effect), 3) trace-metal cation content of sea water (major effect), whereas that of xanthine could be traced only to photolysis.These results cast doubt on previous reports of utilization of uric acid as N-source for phototrophic growth of marine planktonic algae in that the compound actually utilized may be degradation product(s) rather than the intact purine. Ecologically, the results signify that uric acid could undergo rapid chemical turnover, without biological intervention, in the marine environment.

Experimental Study on Bond Behavior of Profiled Steel Sheet-Lightweight Aggregate Concrete Composite Slab

2012 ◽  
Vol 594-597 ◽  
pp. 721-724
Author(s):  
Yan Kun Zhang ◽  
Yan Xiao Han ◽  
Ze Zao Song
Keyword(s):  
Experimental Study ◽  
Steel Sheet ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Composite Slab ◽  
Bond Behavior ◽  
Ordinary Concrete ◽  
Relationship Of ◽  
The Relationship

At present, there are much more researches on the ordinary concrete composite slab, and that on the lightweight aggregate concrete composite slab are relatively less. In this paper, the shear-bond behavior of lightweight aggregate concrete composite slab, with the profiled steel sheet YX-76-344-688, which is commonly used in China is studied. Base on experiments, the cracks developing process and its regularities of distribution, the bonding and slipping between profiled sheeting and concrete, the relationship of load and mid-span deflection, ultimate bearing capacity etc. are studied.

scholarly journals Sulfur Nutrition Affects Cellular Sulfur, Dry Weight Distribution, and Bulb Quality in Onion

2001 ◽  
Vol 126 (2) ◽  
pp. 164-168 ◽  
Author(s):  
Jane E. Lancaster ◽  
Julie Farrant ◽  
Martin L. Shaw
Keyword(s):  
Cell Wall ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Major Effect ◽  
Soluble Solids ◽  
Minor Effect ◽  
Cell Wall Proteins ◽  
Onion Bulbs ◽  
Solids Concentration ◽  
Cell Fractions

Three onion (Allium cepa L.) cultivars, `Southport White Globe', `Grano', and `Pukekohe Longkeeper' were grown at low to high S (at 0.5, 1.8, 3.0 or 4.0 meq·L-1) in hydroponic culture. Differential solvent extractions of bulbs were used to isolate quantitatively cell contents, cell wall proteins, and cell wall residue. The weight of the cell fractions, their S content, and the S content of intact bulbs were determined. Bulb characteristics of fresh weight (FW), firmness, soluble solids concentration (SSC), and soluble sugars were also determined. For all three cultivars, bulb FW increased with S from 0.5 to 4.0 meq·L-1. Sulfur had a significant effect on bulb firmness. Onion bulbs grown with S at 0.5 meq·L-1, the lowest S concentration, were significantly softer than onion bulbs grown at the highest concentration of 4.0 meq·L-1. Varying the S supply had a major effect on dry weight (DW) allocation to the cell wall residue. Bulbs of all three cultivars grown at the lowest S had significantly less DW in the cell walls compared to S at 3.0 or 4.0 meq·L-1. In contrast to the effect of S supply on DW allocation, varying S supply had no effect on total bulb S, free SO4-2, and on the S content of the cell contents and the cell wall residue and only a minor effect on cell wall proteins. There was no significant effect of S supply on either SSC or soluble sugars. At low S nutrition, which is limiting to the growth of onion bulbs, cell wall deposition is reduced, with a consequent decrease in bulb firmness. The S composition of the cellular components is maintained at the expense of bulb growth.

scholarly journals Structural Behavior of Composite Floor System Using Cold-Formed Thin-Walled C Steel Channel Embedded Foam Concrete

2021 ◽  
Vol 11 (21) ◽  
pp. 9888
Author(s):  
Dianzhong Liu ◽  
Feng Fu ◽  
Wanjuan Liu
Keyword(s):  
Failure Modes ◽  
Concrete Slab ◽  
Structural Behavior ◽  
Test Results ◽  
Foam Concrete ◽  
Flexural Capacity ◽  
Composite Slab ◽  
New Type ◽  
Thin Walled ◽  
Floor System

In this paper, a new composite floor system using cold-formed thin-walled C steel channel embedment and a foam concrete slab is developed. This new type of floor system features lightweight, high fire-resistant, and high anti-corrosion features, and can be used for multi-story buildings, providing a promising new alternative floor system for the construction market. Two four-point bending tests were carried out to investigate the flexural capacity and failure modes of this new type of composite slab. Based on the test results, a nonlinear finite element model was developed using general software package ABAQUS. The model is validated using the test results. Using this model, parametric studies were performed to study the key parameters affecting the structural behavior of this new type of composite floor system. Different parameters such as density of the foam concrete, grade of the cold-formed thin-walled C steel channel embedment, and spacing of the cold-formed thin-walled C steel channel were investigated. Their contributions to the overall moment capacity and their effect on the failure modes of this type of composite slab were discovered. Based on experimental results and FE results, design formulas for ultimate flexural capacity of this new type of composite slabs were also developed which can accurately predict their flexural capacity.

scholarly journals A Hitchhiker’s guide to the potato wart disease resistance galaxy

2020 ◽  
Vol 133 (12) ◽  
pp. 3419-3439
Author(s):  
Charlotte Prodhomme ◽  
Gert van Arkel ◽  
Jarosław Plich ◽  
Jasper E. Tammes ◽  
Johan Rijk ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Potato Breeding ◽  
Major Effect ◽  
Minor Effect ◽  
Wart Disease ◽  
The South ◽  
Potato Wart ◽  
Resistance Sources ◽  
Potato Wart Disease ◽  
A Genome

Abstract Key message Two novel major effect loci (Sen4 and Sen5) and several minor effect QTLs for potato wart disease resistance have been mapped. The importance of minor effect loci to bring full resistance to wart disease was investigated. Using the newly identified and known wart disease resistances, a panel of potato breeding germplasm and Solanum wild species was screened. This provided a state-of-the-art “hitch-hikers-guide” of complementary wart disease resistance sources. Abstract Potato wart disease, caused by the obligate biotrophic soil-born fungus Synchytrium endobioticum, is the most important quarantine disease of potato. Because of its huge impact on yield, the lack of chemical control and the formation of resting spores with long viability, breeding for resistant varieties combined with strict quarantine measures are the only way to efficiently and durably manage the disease. In this study, we set out to make an inventory of the different resistance sources. Using a Genome-Wide Association Study (GWAS) in the potato breeding genepool, we identified Sen4, associated with pathotypes 2, 6 and 18 resistance. Associated SNPs mapped to the south arm of chromosome 12 and were validated to be linked to resistance in one full-sib population. Also, a bulked segregant analysis combined with a Comparative Subsequence Sets Analysis (CoSSA) resulted in the identification of Sen5, associated with pathotypes 2, 6 and 18 resistance, on the south arm of chromosome 5. In addition to these two major effect loci, the GWAS and CoSSA allowed the identification of several quantitative trait loci necessary to bring full resistance to certain pathotypes. Panels of varieties and Solanum accessions were screened for the presence of Sen1, Sen2, Sen3, Sen4 and Sen5. Combined with pedigree analysis, we could trace back some of these genes to the ancestral resistance donors. This analysis revealed complementary resistance sources and allows elimination of redundancy in wart resistance breeding programs.

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