scholarly journals Performance Test for Sulfate Resistance of Concrete by Tensile Strength Measurements: Determination of Test Criteria

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1018
Author(s):  
Johannes Haufe ◽  
Anya Vollpracht ◽  
Thomas Matschei
Keyword(s):  
Tensile Strength ◽  
Performance Test ◽  
Sulfate Solution ◽  
Sulfate Attack ◽  
Test Method ◽  
Threshold Values ◽  
European Standard ◽  
Sulfate Resistance ◽  
Concrete Mixtures

The European standard EN 206-1 contains descriptive requirements for concrete to withstand sulfate attack in the field. This approach limits the use of feasible concrete mixtures that don’t comply with these requirements. A performance approach based on the residual tensile strength of concrete briquet specimen according to ASTM C307 after storage in sodium sulfate solution close to field conditions is suggested by the authors. The newly developed test method is verified on a variety of 23 binders. Threshold values for the determination of the sulfate resistance of concrete after nine months of storage in 6000 mg SO42−/L sulfate solution at 5 °C are proposed. A first repeatability test as well as thermodynamic calculations prove the suitability of the method to test the performance of concrete during sulfate attack under practical conditions.

scholarly journals Development of a Sulfate Resistance Performance Test for Concrete by Tensile Strength Measurements: Determination of Test Conditions

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1001
Author(s):  
Johannes Haufe ◽  
Anya Vollpracht ◽  
Thomas Matschei
Keyword(s):  
Tensile Strength ◽  
Performance Test ◽  
Storage Temperature ◽  
Direct Method ◽  
Sulfate Solution ◽  
Test Methods ◽  
Experimental Investigations ◽  
Sulfate Resistance ◽  
Binder Type ◽  
Physical Resistance

Assessing the sulfate resistance of concrete is essential for the use of concrete in sulfate rich environments. A multitude of test methods exists worldwide, showing the relevance of the problem and the difficulty to find a suitable test setup. Testing the relative tensile strength of ASTM C307 concrete briquette specimens after exposure to a sulfate solution is a new direct method to assess the degree of deterioration. The aim of this study is to develop a new performance test, which considers both the chemical and physical resistance of a specific concrete mix against sulfate attack. In the experimental investigations, the binder type, storage temperature, type and concentration of sulfate solution, and concrete composition were varied, and the remaining tensile strength evaluated to define the test parameters. To gain significantly distinguishable data within nine months of storage, the use of sodium sulfate solution with 6000 mg SO42−/l at 5 °C is proposed.

Prüfverfahren zur Ermittlung des Krümmungseinflusses auf die Zugfestigkeit von Textilbeton/Test method for the determination of curvature-dependent effects on the tensile strength of textile reinforced concrete

Bauingenieur ◽  
2018 ◽  
Vol 93 (11) ◽  
pp. 454-462
Author(s):  
D. Meßerer ◽  
B. Heiden ◽  
J. Bielak ◽  
K. Holschemacher
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Test Method ◽  
Textile Reinforced Concrete

Der Verbundwerkstoff Textilbeton wird neben der Verwendung für Neubauteile überwiegend zur Verstärkung von Stahlbetonbauteilen eingesetzt. Die Verstärkung von flächigen Bauteilen mit Textilbeton war und ist bereits Gegenstand aktueller Forschungen, die unter anderem zu einem bauaufsichtlich zugelassenen System für diesen Anwendungsfall führten. Beim Einsatz von Textilbeton in gekrümmten Bereichen, wie bei der Umschnürung von stabförmigen Druckgliedern oder der nachträglichen Querkraftverstärkung von Balken, besteht jedoch noch erheblicher Forschungsbedarf. Insbesondere die Auswirkungen der durch die Krümmung entstehenden Einflüsse aus Querdruck, Abknicken der Faserstränge durch kleine Umlenkradien und lokal auftretender Spannungsspitzen an Rissufern sind bisher nicht quantifizierbar und können bei der Bemessung nicht ausreichend berücksichtigt werden. Die Verwendung eines Prüfverfahrens zur Ermittlung des Krümmungseinflusses auf Verstärkungsschichten aus Textilbeton ermöglicht eine differenziertere Betrachtung der festigkeitsmindernden Einflüsse. Die Ergebnisse der durchgeführten Validierungsversuche bestätigen die Relevanz des vorgestellten Prüfverfahrens und ermöglichen die Darstellung der krümmungsabhängigen Festigkeitsminderung für das geprüfte Verstärkungssystem. Zudem lässt sich feststellen, dass besonders bei kleinen Umlenkradien eine höhere Festigkeitsminderung vorliegt, die bisher keine Berücksichtigung fand.

scholarly journals Performance Testing of Hydraulic Cements: Measuring Sulfate Resistance

2018 ◽  
Vol 123 ◽  
Author(s):  
Chiara F. Ferraris ◽  
Paul E. Stutzman ◽  
Max Peltz
Keyword(s):  
Test Procedure ◽  
Performance Testing ◽  
Rapid Test ◽  
Sulfate Solution ◽  
Cementitious Materials ◽  
Decision Time ◽  
Test Method ◽  
Test Duration ◽  
Test Protocol ◽  
Sulfate Resistance

The sulfate resistance of cements used in the construction industry is traditionally assessed by measuring the expansion of a prism of 280 mm (11inch) length and 25 mm (1 inch) square cross section immersed in a sodium sulfate solution for at least one year. The duration of the experiment limits this test from being used as a performance-based determination of innovative mixtures of cementitious materials. In response to the need for a more rapid test protocol, the National Institute of Standards and Technology (NIST) has developed a new test method that measures the expansion of smaller bars (10 mm x 10 mm x 60 mm) made with neat cement paste. With these bars, similar expansion is achieved in less than 3 months, reducing the test duration by a factor of at least 4. This accelerated test method provides more rapid results consistent with the traditional test procedure, allowing for a shorter decision time and the screening of more materials.

Preparation and Performance of Sulfate Resistance Cement-Based Material

2008 ◽  
Vol 400-402 ◽  
pp. 195-201
Author(s):  
Feng Chen Zhang ◽  
Bao Guo Ma ◽  
Geng Yin ◽  
Yuan Yuan Wu ◽  
Yan Chao Zhu
Keyword(s):  
Magnesium Sulfate ◽  
Energy Dispersive Spectrometer ◽  
Sulfate Solution ◽  
Sulfate Attack ◽  
Surface Erosion ◽  
Initial Surface ◽  
Control Specimen ◽  
X Ray ◽  
Sulfate Resistance ◽  
Magnesium Sulfate Solution

To discuss prevention of sulfate attack, especially thaumasite form of sulfate attack (TSA), sulfate resistance cement based material (SRM) were designed and prepared, and properties of which were investigated systematically. Micro-analytical techniques were introduced to identify erosion substances especially thaumasite, namely Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with X-ray energy dispersive spectrometer(EDS). Results show that SRM have better sulfate resistance, as well as TSA resistance, when exposed to aggressive environment with 33800 ppm mass concentration of SO42- in magnesium sulfate solution at 5°C±2°C. When immersed in magnesium sulfate solution for 40 weeks, compressive strength and tensile strength of SRM are still higher than their initial, and those of control specimen are lower by 33.7%, 36.5% compared to its initial. Surface erosion substances of SRM named S1 are ettringite and gypsum, while those of control specimen are ettringite, gypsum, thaumasite and brucite.

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