Transition to the Assessment of the Brickwork Quality in Terms of Compressive Strength Class

2021 ◽  
pp. 131-137
Author(s):  
V. S. Lesovik ◽  
Yu. A. Belentsov ◽  
A. A. Klementyeva ◽  
M. Yu. Elistratkin
Keyword(s):  
Compressive Strength ◽  
Strength Class

scholarly journals INFLUENCE OF STIFFNESS RELATED TO THE C40 STRENGTH CLASS OF THE HARDWOOD GROUP ESTABLISHED BY THE BRAZILIAN STANDARD IN THE DESIGN OF TIMBER STRUCTURES

Wood Research ◽  
2021 ◽  
Vol 66 (4) ◽  
pp. 582-594
Author(s):  
FRANCISCO ANTONIO ROCCO LAHR ◽  
VINICIUS BORGES DE MOURA AQUINO ◽  
FELIPE NASCIMENTO ARROYO ◽  
HERISSON FERREIRA DOS SANTOS ◽  
SERGIO AUGUSTO MELLO SILVA ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Confidence Interval ◽  
Strength Characteristic ◽  
Structural Design ◽  
Strength Class ◽  
Reference Value ◽  
Timber Structures ◽  
Average Confidence ◽  
The One ◽  
Brazilian Standard

The Brazilian standard ABNT 7190 (1997) establishes the strength classes C20, C30, C40 and C60 for the proper framework of the different wood types in the group of hardwoods. Associated with the strength class, which is based on the compressive strength characteristic value parallel to the fibers (fc0,k), the standard stipulates the respective values representing the stiffness (Ec0), with 19500 MPa being the reference value for the class C40, essential variables in structural design. For being the C40 class is the one with the greatest amplitude (20 MPa), it is possible that the value 19500 MPa is not the best representation of stiffness. This work aimed to verify the representativeness the stiffness value established by the Brazilian standard for C40 wood. The result obtained from the average confidence interval indicates the value of 14110 MPa as being the most representative, which may imply structures that are supposedly more rigid than they really are.

scholarly journals Petrographic and Mechanical Characteristics of Concrete Produced by Different Type of Recycled Materials

Geosciences ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 264 ◽  
Author(s):  
Petros Petrounias ◽  
Panagiota P. Giannakopoulou ◽  
Aikaterini Rogkala ◽  
Paraskevi Lampropoulou ◽  
Basilios Tsikouras ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Mechanical Characteristics ◽  
Strength Class ◽  
Concrete Strength ◽  
Glass Waste ◽  
Recycled Materials ◽  
Curing Conditions ◽  
Different Types ◽  
Green Glass ◽  
Water Saturated

This paper examined three different types of recycled materials, such as beer green glass, waste tile, and asphalt, which will be used in different mixtures in order to prepare concrete specimens and, more specifically, their effect on concrete strength and how the petrographic characteristics of various recycled materials influenced the durability of C25/30 strength class concrete. Particular emphasis was placed on the effect of artificial microroughness of glassy and smooth surfaces of recycled materials on their final concrete strength. The concrete strength values do not show great variance, but their limited differences have been qualitatively interpreted by a new promising petrographic methodology, including the study of the surface texture of the used aggregate materials. Concretes are produced with constant volume proportions, workability, mixing, and curing conditions while using different sizes of each aggregate type. The aggregates were mixed both in dry and water saturated states in concretes. Concretes that are made by a mixture of beer green glass with quartz primer, as well as of tile with quartz primer, presented the optimum possible results of the compressive strength.

High-Effective Lightweight Aggregate Obtained from Glass-Containing Waste

2020 ◽  
Vol 787 (12) ◽  
pp. 66-71
Author(s):  
H.N. Mammadov ◽  
◽  
I.H. Suleymanova ◽  
B.M. Tahirov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Strength Class ◽  
Physical And Mechanical Properties ◽  
Lightweight Aggregate ◽  
High Strength ◽  
Raw Material ◽  
Material Base ◽  
Current Standard ◽  
Iron And Steel

The properties of high-strength artificial porous aggregate from glass-containing waste of metallurgical productions are described. The developed technology makes it possible to expand the raw material base for the production of aggregates for light concrete. Granulated slags of metallurgical productions – the main (M0>1) slags of the Novokuznetsk Iron and Steel Plant and acid (M0<1) slags of the Gorky plant are studied. According to the results of studies, it was found that the optimal swelling interval for acidic slags is 1000–1100оC, and for basic slags-1100–1150оC. A high – strength artificial porous aggregate-slag gravel with a bulk density of 340–780 kg/m3 and a compressive strength in the cylinder of 2.8–12.3 MPa was obtained. The main physical and mechanical properties of the resulting aggregate, which meets the requirements of the current standard GOST 9757–90 “Gravel, crushed stone and sand. Artificial porous”, were studied. The aggregate obtained is almost twice as strong as the known aggregate of expanded clay gravel. With the use of porous gravel and sand, light concrete of strength class B7,5–B40 and a density of 1100–1600 kg/m3 was obtained.

scholarly journals HYDROTECHNICAL CONCRETE WITH LOCAL AGGREGATES AND THEM USING FOR MONOLITHIC STRUCTURES

2009 ◽  
Vol 1 (2) ◽  
pp. 102-110
Author(s):  
Vigantas Antanas Žiogas ◽  
Svajūnas Juočiūnas ◽  
Giedrius Žiogas
Keyword(s):  
Compressive Strength ◽  
Mass Loss ◽  
Frost Resistance ◽  
Strength Class ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Water Penetration ◽  
Total Mass Loss ◽  
Micro Cracks

The article discusses the technological peculiarities of construction monolithic hydrotechnical concrete structures, use of local aggregates for producing special concretes, methods of determining water impermeability of concretes as well as the evaluation of the methods mentioned above. The article presents the requirements for the granulometric composition of aggregate mixes for the production of flowing concrete mixes used for the construction of monolithic hydrotechnical structures. The possibilities and expediency of using local crushed gravel with increased amounts of weak particles for hydrotechnical structures are discussed. The mass loss of weak particles is slight compared with the whole mass of aggregates, and the total mass loss of crushed gravel it occurs due to micro-cracks present in particles. The frost resistance mark of crushed gravel and its suitability for hydrotechnical concretes should be determined by evaluating the amount of weak particles and their frost resistance. The article discusses concrete impermeability data received by means of two methods (according to LSTST 1974:2005 and LSTST EN 12390–8 requirements). Theoretical water penetration depths have been calculated. Determination of water impermeability according to LSTST 1974:2005 is recommended for C25/30 and lower compressive strength class concretes with W≤8. The LSTST EN 12390–8 water impermeability determina-tion method is recommended for C25/30 and higher compressive strength class concretes whose water impermea-bility mark is W≥8. For the construction of certain hydrotechnical structures water impermeable concretes whose water penetration depth should not exceed 20mm are recommended for use instead of the W6 and W8 concretes. Technological peculiarities and potential technological-organizational solutions for high walls of a water treatment plant have been discussed. The analysis of potential concreting methods of the reservoir’s high walls has been made as well as that of the key parameters of the continuous concreting process and their interaction. Dependences for the estimation of continuous concreting volumes and permissible concreted segment lengths have been proposed by evaluating the beginning of the intensive formation structure of concrete, number of layers in the height of the concreted wall and concreting intensity.

Evaluation of the Modulus of Elasticity of Different Types of Concrete Compared with Eurocode 2

2016 ◽  
Vol 677 ◽  
pp. 181-185
Author(s):  
Klára Křížová ◽  
Rudolf Hela
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Strength Class ◽  
Raw Materials ◽  
Concrete Strength ◽  
Experimental Part ◽  
Static Modulus ◽  
Eurocode 2 ◽  
Different Types ◽  
Static Modulus Of Elasticity

The comparison of really measured compressive strength static modulus of elasticity with table values stated in Eurocode 2 is essential part of the paper. Since the standard draws from modulus of elasticity - concrete strength class, the set compressive strengths will be classified in concrete particular classes. Experimental part was based on several concrete design compositions differing in particular input raw-materials. Monitored values were set with concretes in different ages with final value 180 days. The experiment tries to demonstrate the impossibility of static modulus of elasticity derivation from table values which do not match the present-date produced concretes.

The Effects of Cement Content, Sand Percentage and Fly Ash Dosage on Lightweight Aggregate Concrete

2006 ◽  
Vol 302-303 ◽  
pp. 282-287
Author(s):  
Liu Wei ◽  
Feng Xing ◽  
Lu Han
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Strength Class ◽  
Cement Content ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Ongoing Research ◽  
Aggregate Concrete ◽  
Structural Lightweight Aggregate Concrete

The paper is one part of ongoing research on structural lightweight aggregate concrete. Lightweight aggregate concrete with compressive strength class of CL40 and slump of 160-200 mm were studied. The influences of the cement content, sand percentage and fly ash dosage on properties of fresh and hardened LWAC, such as fresh density, workability and compressive strength were investigated.

scholarly journals Moisture Influence on Compressive Strength of Calcium Silicate Masonry Units–Experimental Assessment and Normative Calculations

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3817
Author(s):  
Halina Garbalińska ◽  
Jarosław Strzałkowski ◽  
Agata Stolarska
Keyword(s):  
Compressive Strength ◽  
Strength Class ◽  
High Accuracy ◽  
Spectroscopy Analysis ◽  
Porosity Structure ◽  
Different Types ◽  
Moisture Influence ◽  
The Relationship ◽  
Masonry Units ◽  
Microstructural Studies

This paper primarily assesses the scale of adverse changes to the compressive strength of different types of silicates due to the influence of moisture. The study covers three groups of silicate units of different strength classes—15, 20 and 25—obtained from three different manufacturers. It was demonstrated that in all studied groups, moisture significantly decreased the compressive strength by about 30–40%. In addition, microstructural studies were conducted to analyze the relationship between the specific porosity structure of each group of silicate bricks and their compressive strength. On the basis of SEM (Scanning Electron Microscopy) and EDS (Electron Dispersive Spectroscopy) analysis, the elemental composition of individual silicates was determined and the contact zone between the aggregate and the binder was determined, which largely influenced the obtained compressive strength of each silicates. Next, the study referred to the utility of the normative procedure used to determine the strength class of samples with different geometries and at different moisture concentrations. The results of the calculations showed the high accuracy of the normative-based assessment of strength class, regardless of the manufacturer and the moisture values during examination.

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