scholarly journals The effect of synthetic zeolite admixture on the durability of concrete paving blocks

2016 ◽  
Vol 11 (3) ◽  
pp. 215-221 ◽  
Author(s):  
Giedrius Girskas ◽  
Džigita Nagrockienė ◽  
Gintautas Skripkiūnas
Keyword(s):  
Synthetic Zeolite ◽  
Test Results ◽  
Absorption Increase ◽  
Splitting Strength ◽  
Aluminium Fluoride ◽  
Tensile Splitting Strength ◽  
The Baltic ◽  
Stone Concrete ◽  
Concrete Elements ◽  
Durability Of Concrete

Concrete paving blocks that were started to be used in the last century have become very popular. They became an alternative to the natural stone. Concrete paving blocks are used for the paving of pedestrian and vehicle zones. Durability is one of the main characteristics in the production of high-quality concrete paving blocks in the Baltic region climate zone. The article describes tests with concrete paving blocks, the top layer of which contains 5% of synthetic zeolite admixture obtained by means of low temperature synthesis in laboratory conditions. This zeolite admixture is obtained from aluminium fluoride production waste. The durability of concrete paving blocks was tested according to abrasion resistance, tensile splitting strength, absorption and frost resistance. The test results revealed that 5% of zeolite admixture added to the top layer of concrete paving blocks reduce the absorption, increase the tensile splitting strength by more than 10%, and decrease abrasion by 6.5%. The zeolite admixture used in concrete paving blocks reduces the scaling about 4 times after 28 freeze-thaw cycles when 3% NaCl is used as the freezing solution. The tests revealed that synthetic zeolite admixture can be used in concrete elements production by means of vibropressing (pavement elements) to increase their durability.

Zeolite Influence of Vibropressing Concrete Durability

2017 ◽  
Vol 908 ◽  
pp. 71-75 ◽  
Author(s):  
Giedrius Girskas
Keyword(s):  
Low Temperature ◽  
Aluminum Fluoride ◽  
Concrete Durability ◽  
Test Results ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Absorption Increase ◽  
Splitting Strength ◽  
Tensile Splitting Strength ◽  
Durability Of Concrete

Durability is one of the main characteristics in the production of high-quality concrete paving blocks in the Baltic region climate zone. Concrete paving blocks are produced by means of vi bropressing , dimensions: 198×98×80 mm . The article describes tests with concrete paving blocks, the top layer of which contains 5% of zeolite admixture obtained from waste of aluminum fluoride production by low-temperature synthesis. The durability of concrete paving blocks was tested according to abrasion resistance, tensile splitting strength, absorption and frost resistance. The test results revealed that 5% of zeolite admixture added to the top layer of concrete paving blocks reduce the absorption, increase the tensile splitting strength and decrease abrasion. The zeolite admixture used in concrete paving blocks reduces the scaling about 4 times after 28 freeze-thaw cycles when 3% NaCl is used as the freezing solution. The test results proved that synthetic zeolite obtained from aluminum fluoride by means of low temperature synthesis can be used as a supplementary cementitious material to increase the durability of concrete pavement elements.

Influence of Microwave Treatment on Properties of Concrete with Non-Cyclic Alkanes

2016 ◽  
Vol 677 ◽  
pp. 114-121
Author(s):  
Roman Jaskulski
Keyword(s):  
Water Absorption ◽  
Free Water ◽  
Microwave Treatment ◽  
General Tendency ◽  
Test Results ◽  
Mean Values ◽  
Splitting Strength ◽  
Cyclic Alkanes ◽  
Sorptivity Test ◽  
Tensile Splitting Strength

Influence of exposure to microwave (MW) radiation of concrete with paraffin addition was presented. Specimens were exposed to MW after 7 and 28 days from casting. The exposure times were: 20 minutes and 40 minutes. Concretes were made with 1 and 3% addition of paraffin of the volume of concrete mixture. As a reference served concrete with no paraffin addition and concrete containing paraffin but not treated with MW. Paraffin was added in two forms: as a powder (fine paraffin) and as a granules (coarse paraffin). Influence of radiation on compressive and tensile splitting strength was tested as well as its impact on sorptivity and free water absorption. Exposure to MW radiation lowered the mean values of concrete compressive and tensile splitting strength maximum of about 24%. Sorptivity test results showed no general tendency and free water absorption has decreased maximum about 20%.

scholarly journals BEHAVIOUR OF HOLLOW CONCRETE‐FILLED STEEL TUBULAR COMPOSITE ELEMENTS

2007 ◽  
Vol 13 (2) ◽  
pp. 131-141 ◽  
Author(s):  
Artiomas Kuranovas ◽  
Audronis Kazimieras Kvedaras
Keyword(s):  
Stress State ◽  
Elasticity Modulus ◽  
Complex Stress ◽  
Steel Tube ◽  
Complex Stress State ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Concrete Core ◽  
Theoretical Investigations ◽  
Concrete Elements

Behaviour of composite steel‐concrete elements in various loading stages is quite well analysed by theoretical investigations and experiments. Concrete‐Filled Steel Tube (CFST) is one of many composite elements used at present in civil engineering. Different approaches and design philosophies were adopted in different design codes for it. But for hollow CFST elements, which are more effective than ordinary CFST, any code does not provide information about how to design these elements. Further investigations of hollow composite CFST elements are needed. In loading stage, when a particular level of stresses exists, an interaction between steel tube and concrete core appears and therefore a complex stress state of element takes place, which increases the load‐bearing capacity of the whole composite element. This interaction between components of CFST elements is reached because of different material properties, such as Poisson's ratio, elasticity modulus etc. In this article reasons of the above‐mentioned complex stress state appearance and behaviour of hollow CFST element components in different load stages of compressed stub structural member are analysed. The test results are presented in diagrams, tables. Previous researches of other investigators are summarised. Differences and similarities in behaviour of solid concrete and composite elements and hollow members with different number of concrete core layers are discussed.

scholarly journals Studying the Effect of Syrian Natural Zeolite On Properties of Asphalt Binder

2021 ◽  
Vol 28 (1) ◽  
pp. 59-68
Author(s):  
Mahmoud Ali Abdullh ◽  
Fayez Suleiman ◽  
Bassem Ali ◽  
Adel Dib
Keyword(s):  
Asphalt Concrete ◽  
Natural Zeolite ◽  
Asphalt Binder ◽  
Economic Benefits ◽  
Synthetic Zeolite ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aged Asphalt ◽  
The Cost

In the last years, many researchers studied production of warm asphalt concrete by usingorganic, chemical and water-bearing additive )synthetic zeolite). The purpose of this research is to study theeffect of Syrian natural zeolite on the physical and rheological properties of asphalt binder and verify ofusing it to produce warm asphalt concrete (as a binder modifier or as additive to asphalt concrete), in additionto economic benefits by saving on the cost of synthetic zeolite. In this study, natural zeolite characterizationhas been investigated via X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD) and Thermal Gravimetricanalysis (TGA). Natural zeolite was added to asphalt binder with different percentages (3, 4, 5 and 6%) byweight and to determine the effect of natural zeolite on properties of asphalt binder, penetration at )25(°∁,softening point, ductility, viscosity at (110, 120, 135)°∁ and RTOFT tests were carried out on both modifiedand unmodified aged asphalt binder with natural zeolite. According to the test results, it has been seen thatthe addition of natural zeolite improves properties of the asphalt binder and an increase in its resistance tofatigue, and do not make a substantial difference on the workability of the asphalt binder. So the effect ofthe mixture of natural zeolite additives on the workability could not be predicted on asphalt binder, thereforethe direct effect of additives should be studied on the asphalt mixtures.

scholarly journals Prediction of Plastic Shrinkage Cracking of Self-Compacting Concrete

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Parviz Ghoddousi ◽  
Armin Monir Abbasi ◽  
Esmail Shahrokhinasab ◽  
Mohammad Abedin
Keyword(s):  
Shrinkage Strain ◽  
Climatic Conditions ◽  
Water Evaporation ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Shrinkage Cracking ◽  
Plastic Shrinkage ◽  
The Difference ◽  
The Relationship ◽  
Concrete Elements

Concrete exposed to hot climatic conditions is prone to plastic shrinkage after casting within the first few hours due to the water evaporation and restraining conditions of concrete. This cracking is more commonly observed in concrete elements with a large surface area exposed to drying. In this research, plastic shrinkage of 13 self-compacting concrete samples with different cement paste volumes and various coarse to total aggregate ratios was studied. Test specimens of fresh concrete were subjected to a wind tunnel, which simulated hot dry environmental condition immediately after casting. It can be observed from the test results that the relationship between free plastic shrinkage and the difference between bleeding and evaporation is direct and linear. Finally, a model for plastic shrinkage estimation was suggested by considering the effect of free plastic shrinkage strain, restraining factor, and tensile strain capacity of self-compacting concrete.

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