Structural Impacts of Nonconformity of Concrete in a Multi-Storey Building

2019 ◽  
Author(s):  
Bruno Favoretto Silva ◽  
Carlos Abdalla Name ◽  
Marco Aurélio Tavares Caetano
Keyword(s):  
Compressive Strength ◽  
Global Stability ◽  
Construction Site ◽  
Limit States ◽  
Structural Alterations ◽  
Real Importance ◽  
Structural Impacts ◽  
Resistance Decrease ◽  
Compressive Resistance ◽  
Storey Building

<p>The goal of this paper is to analyse all the impacts and structural alterations a multi-storey building may have when the compressive strength of the concrete is not respected, as well as point how the global stability of the structure can be affected by such compressive resistance decrease. In order to obtain accurate results, real projects data were taken from a construction site in Goiânia, Brazil. Moreover, structural simulations were performed through TQS Software so that the not previously foreseen nonconformities could be analysed and the problems related to the Ultimate/Serviceability Limit States could be avoided. The simulations consisted on the analysis of compressive strengths of 35 and 40 MPa. From this work, it is possible to detect substantial reasons to respect the real importance of the concrete’s fck. Overall, the element with lower fck is more vulnerable to excessive deflection and cracks.</p>

scholarly journals Designing the Composition of Cement Stabilized Rammed Earth Using Artificial Neural Networks

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1396 ◽  
Author(s):  
Hubert Anysz ◽  
Piotr Narloch
Keyword(s):  
Neural Networks ◽  
Compressive Strength ◽  
Artificial Neural Networks ◽  
Rammed Earth ◽  
Particle Sizes ◽  
Construction Site ◽  
Construction Technique ◽  
Soil Cement ◽  
Energy Consuming ◽  
Artificial Neural

Cement stabilized rammed earth (CRSE) is a sustainable, low energy consuming construction technique which utilizes inorganic soil, usually taken directly from the construction site, with a small addition of Portland cement as a building material. This technology is gaining popularity in various regions of the world, however, there are no uniform standards for designing the composition of the CSRE mixture. The main goal of this article is to propose a complete algorithm for designing CSRE with the use of subsoil obtained from the construction site. The article’s authors propose the use of artificial neural networks (ANN) to determine the proper proportions of soil, cement, and water in a CSRE mixture that provides sufficient compressive strength. The secondary purpose of the paper (supporting the main goal) is to prove that artificial neural networks are suitable for designing CSRE mixtures. For this purpose, compressive strength was tested on several hundred CSRE samples, with different particle sizes, cement content and water additions. The input database was large enough to enable the artificial neural network to produce predictions of high accuracy. The developed algorithm allows us to determine, using relatively simple soil tests, the composition of the mixture ensuring compressive strength at a level that allows the use of this material in construction.

scholarly journals Compressive strength and compressive fatigue limit of conventional and high viscosity posterior resin composites

2005 ◽  
Vol 19 (4) ◽  
pp. 272-277 ◽  
Author(s):  
Letícia Brandão ◽  
Gelson Luis Adabo ◽  
Luís Geraldo Vaz ◽  
José Roberto Cury Saad
Keyword(s):  
Compressive Strength ◽  
Fatigue Limit ◽  
Compression Strength ◽  
Dynamic Test ◽  
High Viscosity ◽  
Composite Resins ◽  
Resin Composites ◽  
Strength Ratio ◽  
Staircase Method ◽  
Compressive Resistance

The purpose of this study was to compare the compressive strengths and compressive fatigue limits of three posterior composite resins (Filtek P-60, Surefil and Prodigy Condensable) and a universal restorative composite (Z-100). Cylindrical specimens (8 mm in length x 4 mm in diameter) were used. The dynamic test was performed using the staircase method, and the ratio between compressive fatigue limit and compressive resistance was also calculated (n = 15). The compressive strength and compressive fatigue limit data were analyzed by Anova and Tukey’s test. The Z-100 composite demonstrated higher compression strength (307.20 MPa) than Surefil (266.93 MPa) and Prodigy Condensable (222.08 MPa). The resistance of Filtek P-60 (270.44 MPa) was similar to the resistances of Z-100 and Surefil, while Prodigy Condensable presented the lowest compressive strength. In the compressive fatigue limit tests, Filtek P-60 demonstrated a higher value (184.20 MPa) than Prodigy Condensable (155.50 MPa). Surefil (165.74 MPa) and Z-100 (161.22 MPa) presented limits similar to those of Filtek P-60 and Prodigy Condensable. The compressive fatigue limit/compressive strength ratio was 70.01% for Prodigy Condensable, 68.11% for Filtek P-60, 62.09% for Surefil and 52.48% for Z-100. It was concluded that the Z-100 universal composite was more sensitive to the dynamic test than the high viscosity materials.

scholarly journals Resistencia de concreto con agregado de alta absorción y baja relación a/c

2012 ◽  
Vol 2 (1) ◽  
pp. 21-28
Author(s):  
R. G. Solís ◽  
E. Moreno ◽  
E. Arjona
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Construction Site ◽  
Cement Ratio ◽  
Limestone Aggregate ◽  
Concrete Mixtures ◽  
Water To Cement Ratio ◽  
Maximum Compressive Strength ◽  
Crushed Limestone ◽  
High Absorption

RESUMENLa resistencia del concreto depende de la calidad de la pasta de cemento y de las características de los agregados pétreos. La primera es controlada por la relación agua - cemento, mientras que las propiedades de los agregados generalmente no pueden ser manipuladas ya que se suele utilizar aquellos que están disponibles cerca de la construcción. En muchas regiones rocas con propiedades no deseables son utilizadas como agregado. Por lo tanto, el objetivo de este trabajo fue responder a la pregunta sobre cuál sería la máxima resistencia de diseño que se podría utilizar para concretos fabricados con un tipo específico de agregados obtenidos a partir de la trituración de roca caliza de alta absorción. Se probaron concretos con seis relaciones agua - cemento y dos tamaños de agregado grueso. Se concluyó que con los agregados estudiados es posible fabricar concretos de hasta 500 k/cm2 de f’c.Palabras clave: Absorción; agregados calizos; concreto; relación agua/cemento; resistencia.ABSTRACTConcrete strength depends on the cement paste quality and on the characteristics of the aggregates. The former is controlled by the water to cement ratio, while the properties of the aggregate, in general, cannot be manipulated as it is customary to employ the ones available near the construction site. In many regions rocks with no desirable properties are employed as aggregates. Therefore, the aim of this study was to answer the question about what would that be the maximum compressive strength attainable in concrete made with a specific type of aggregate obtained from crushed limestone of high absorption. Concrete mixtures involved six water to cement ratios and two sizes of coarse aggregate. It was concluded that with this type of aggregate it is possible to made concrete with compressive strength up to 500 k/cm2 of f’c.Key words: Absorption; compressive strength; concrete; limestone aggregate; water/cement ratio.

scholarly journals Strength Characteristics of Cement Treated and Expanded Polystyrene Mixed Lightweight of Waste Soil from the Construction Site of a Yangtze River Bridge in China

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Weihua Lu ◽  
Jianyun Wang ◽  
Yongxing Zhang
Keyword(s):  
Compressive Strength ◽  
Yangtze River ◽  
Raw Materials ◽  
Fine Sand ◽  
Expanded Polystyrene ◽  
Strength Characteristics ◽  
Construction Site ◽  
Exponential Relationship ◽  
Construction Waste ◽  
Waste Soil

In the past decades, the speed and scale of Chinese infrastructure construction have been enormous, and the resulting construction waste is also quite amazing, which has become a huge threat to environmental protection. If the pollution-free engineering utilization of the construction waste can be achieved at a low cost, it will undoubtedly be a great benefit for the country and the people. Therefore, a preliminary experimental study was conducted to investigate the strength characteristics of the cement treated and expanded polystyrene mixed lightweight. The waste soil (muddy clay and fine sand) as the main component of the lightweight mixture is taken from a foundation construction site of a Yangtze River Bridge which connects two eastern coastal cities, Zhenjiang and Yangzhou. With different mixture ratios and additives of the cement treated and expanded polystyrene mixed lightweight, a series of cubic samples were tested by the unconfined compressive strength test, and collections of standard cylinder samples prepared by hand were inspected by the conventional triaxial shear test. Then, a good exponential relationship between the uniaxial compressive strength and the cement mixing ration was founded, and a logarithmic relationship was captured between the compressive strength and curing time within a period of 28 days after the specimens were made. Samples made of different soil as raw materials have different strengths, but all of these specimens show a strain-hardening and stable behavior. Results show that the mechanical strength characteristics of the cement treated and expanded polystyrene mixed waste soil mainly depend on the proportions of lightweight mixture.

Probabilistic Compressive Strength of Stiffened Steel Plates Exhibiting Column-Like Behavior: Ultimate and Serviceability Limit States

2020 ◽  
Vol 146 (9) ◽  
pp. 04020166
Author(s):  
Mahmudur Rahman ◽  
Yoshiaki Okui ◽  
Masato Komuro ◽  
Muhammad Atif Anwer ◽  
Azusa Numata
Keyword(s):  
Compressive Strength ◽  
Steel Plates ◽  
Limit States ◽  
Stiffened Steel

Effects of Changing Double Angles Configuration Used as Braces in Seismic Resisting Systems

2018 ◽  
Vol 763 ◽  
pp. 279-286
Author(s):  
Carlos Bermudez ◽  
Oscar Gutierrez
Keyword(s):  
Compressive Strength ◽  
Slenderness Ratio ◽  
Limit State ◽  
Experimental Results ◽  
Limit States ◽  
Torsional Buckling ◽  
Critical Limit ◽  
Flexural Buckling ◽  
Flexural Torsional Buckling ◽  
Buckling Length

Seismic resisting systems consisting of double angles are used in many parts of the world. Generally, these double angles are arranged in the shape of a T, with a very small distance between them. However, sometimes these angles are distanced and faced in order to improve their mechanical characteristics about the axis of symmetry. In the past, their design was made in the same way as the double angles arranged in a T shape, that is, considering the limit states of flexural buckling and buckling by flexural-torsional, but ignoring the properties of the connectors and their effect on the modified slenderness ratio, as well as the fact that in this case the warping constant is not negligible. These parameters are taken into account in this research in order to study the effects of increasing the distance between the connectors and their possible use as braces in seismic resisting systems. The theoretical results were compared with the experimental results of fifty-seven specimens tested in the laboratory of structures of the Universidad Nacional de Colombia – Sede Manizales. The models were classified according to the main angles, the connectors, the total lengths, and the width of separation. All of them were subjected to axial compressive stress, with free rotation at both ends. Three identical specimens of each model were constructed. The flexural buckling length about x-axis was limited to two meters in all specimens tested whereas the flexural bucking length about y-axis and flexural-torsional buckling length were not limited, i.e. these lengths are equivalent to the total length of each specimen tested. This in order that the critical limit state was to be the flexural-torsional buckling as a function of the torsional buckling term in Z, except in the models of class 2 in which this induced condition was not reached. This was proposed to better evaluate the torsional buckling term in Z. The experimental results show that the nominal compressive strength for the flexural-torsional buckling limit state, when it is governed by torsion, is undervalued. A new methodology is proposed for the calculation of the nominal compressive strength for the flexural-torsional buckling limit state, when it is governed by torsion.

Slenderness ratio of main members between interconnectors of built-up compression members

1996 ◽  
Vol 23 (6) ◽  
pp. 1295-1304 ◽  
Author(s):  
Murray C. Temple ◽  
Ghada M. Elmahdy
Keyword(s):  
Slenderness Ratio ◽  
Steel Structures ◽  
Imperfection Sensitivity ◽  
Design Standards ◽  
Limit States ◽  
Compression Members ◽  
Equivalent Slenderness Ratio ◽  
The Individual ◽  
Compressive Resistance ◽  
Steel Design

Many steel design standards, including CAN/CSA-S16.1-M89 "Limit states design of steel structures," specify maximum slenderness ratios for the individual main members between the interconnectors of built-up compression members. Previous research on which these requirements are based is reviewed. It is shown that the imperfection sensitivity due to coupled instabilities is measured from bifurcation critical loads. However, steel standards are based on a compressive resistance determined for a member with an initial out-of-straightness and a suitable residual stress pattern. It is shown that the use of an equivalent slenderness ratio equation is sufficient to predict the compressive resistance of these built-up members. Further restrictions on the slenderness ratio of built-up members between interconnectors are not warranted. Thus, the elimination of these requirements from S16.1-94 is justified. Key words: built-up members, codes, compressive resistance, coupled instabilities, equivalent slenderness ratio, interconnectors.

scholarly journals Fire resistance of ceramic-masonry sealing blocks using intumescent paint protection

2019 ◽  
Vol 10 (1) ◽  
pp. 53-68
Author(s):  
Carlos Alexandre Santos Sales ◽  
Carlos Fernando Gomes do Nascimento ◽  
Thais Marques da Silva ◽  
Lydia Marques Barreto ◽  
Alberto Casado Lordsleem Júnior ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Thermal Insulation ◽  
Fire Resistance ◽  
Mechanical Resistance ◽  
Masonry Structures ◽  
Passive Protection ◽  
Surface Protection ◽  
Direct Exposure ◽  
The Face ◽  
Compressive Resistance

The efficiency of surface protection of sealing masonry structures with intumescent ink was evaluated in relation to mechanical resistance and thermal insulation. Sixty ceramic sealing masonry blocks were used. The temperature of the face directly exposed to the flame was on average 25% lower for the block with passive protection. The compressive strength of the blocks with passive protection was about 70% higher than the unprotected blocks, after 60 minutes of direct exposure to the flame. More than 70% of the blocks without passive protection and that were exposed to flame had compressive resistance of 1.35 MPa, while 100% of the blocks with protection had values 2.38 MPa, even after 60 minutes of exposure

scholarly journals STRENGTHENING OF THE FOUNDATIONS OF RENOVATED BUILDINGS WITH INJECTION PILES

2021 ◽  
Vol 17 (1) ◽  
pp. 75-86
Author(s):  
Anatoly Polishchuk ◽  
Nadezda Nikitina ◽  
Arkady Petukhov ◽  
Ivan Semyonov
Keyword(s):  
Soil Layer ◽  
Soil Conditions ◽  
Building Structures ◽  
Construction Site ◽  
Structural Elements ◽  
Structural Scheme ◽  
Limit States ◽  
Before And After ◽  
Design Loads ◽  
Full Operation

The paper describes the technique of strengthening shallow foundations of reconstructed buildings using injection piles. First, the constructive solution of the existing foundations, the structural scheme of the building, as well as the loads transferred to the building structures before and after its reconstruction are established. At the same time, an assessment of the soil conditions of the construction site of the reconstructed building is carried out; a bearing soil layer is revealed for deepening the lower ends of injection piles. Based on the data obtained, the loading of the base of the foundations of the reconstructed building is assessed and the need for their reinforcement (or further operation without reinforcement) is established. In the case of strengthening the foundations of the building, the method of transferring the additional load to the injection piles is selected. Then their bearing capacity and design loads allowed on the piles are substantiated. The construction of foundations is carried out, taking into account their reinforcement with injection piles, which are hereinafter called combined. Verificationcalculations of the base of the combined foundations are performed for the firstand second groups of limit states. In accordance with the regulatory documents, strength calculations of the main structural elements of foundations are carried out, which are necessary to ensure their full operation, taking into account the reinforcement. At the finalstage, working documentation is developed to strengthen the foundations of the reconstructed building. The stages of the design of strengthening the foundations of reconstructed buildings using injection piles presented in the work allow to properly and consistently organize the work of specialists.

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