scholarly journals Barium carbonate and supplementary cementitious materials to counteract thaumasite sulfate attack in mortars: Effect of aggregate composition

2021 ◽  
Vol 282 ◽  
pp. 122583
Author(s):  
P.M. Carmona-Quiroga ◽  
M.T. Blanco-Varela
Keyword(s):  
Barium Carbonate ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Supplementary Cementitious Materials ◽  
Aggregate Composition

scholarly journals Performa Beton Dengan Ground Granulated Blast Furnace Slag Terhadap Sulfate Attack

2020 ◽  
Vol 16 (3) ◽  
pp. 185
Author(s):  
Rizki Amalia Tri Cahyani ◽  
Ernawan Setyono ◽  
Yunan Rusdianto
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Supplementary Cementitious Materials ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Serangan sulfat (sulfate attack) termasuk hal yang umum terjadi pada struktur beton, mengingat ion sulfat banyak dijumpai pada tanah, air tanah dan air laut. Peningkatan ketahanan beton melawan sulfat akan berdampak besar pada durabilitas dan umur layan struktur beton. Penambahan supplementary cementitious materials seperti GGBFS (ground granulated blast furnace slag) ke campuran beton telah terbukti memberikan pengaruh positif terhadap durabilitas dan properti mekanis beton. Namun, GGBFS tergolong material yang baru dikembangkan di Indonesia dan potensinya dalam meningkatkan durabilitas beton belum dimanfaatkan secara luas. Berdasarkan hal tersebut, perlu dilakukan investigasi terkait aplikasi GGBFS dan pengaruhnya terhadap durabilitas beton, terutama dalam melawan serangan sulfat. Dalam studi ini, durabilitas beton dengan persentase penggantian GGBFS 30%, 50% dan 70% terhadap total volume binder dievaluasi menggunakan perlakuan siklus basah-kering dalam larutan magnesium sulfat. Tingkat degradasi beton diukur dengan melakukan observasi terhadap perubahan kuat tekan dan massa spesimen akibat serangan sulfat. Hasil penelitian menunjukkan bahwa penggantian GGBFS hingga 50% dari total volume binder dapat meningkatkan ketahanan beton terhadap serangan sulfat, ditunjukkan dengan kehilangan massa dan reduksi kekuatan yang lebih rendah dibandingkan spesimen kontrol dengan 100% semen Portland.

scholarly journals Degradation of Shotcrete Materials Subjected to Sulfate and Chloride Attack in Varying Exposure Regimes

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ruiqiang Zhao ◽  
Lihao Xu ◽  
Jun Yang ◽  
Yang Zou ◽  
Zhongya Zhang
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Chloride Ions ◽  
Supplementary Cementitious Materials ◽  
Mineral Admixtures ◽  
Exposure Condition ◽  
Hydration Kinetics ◽  
Partial Immersion

Durability of in situ shotcrete under external sulfate attack was investigated, taking into consideration the addition of mineral admixtures, along with the presence of chloride ions. Three water-to-binder ratios (w/b), i.e., 0.35, 0.45, and 0.55, and two types of supplementary cementitious materials (SCMs), namely, fly ash (FA) and silica fume (SF), were considered in the current study. Two different laboratorial immersion regimes (continuously full immersion and partial immersion with cycling temperature and relative humidity) were carried out to induce chemical/physical sulfate attack. Results show that loss of strength was the typical feature of chemical sulfate attack on shotcrete, while surface spalling dominated in deterioration caused by physical sulfate attack. The presence of chloride ions can globally mitigate these deteriorations. Meanwhile, the lower w/b ratio proved to be efficient in increasing the resistance to both sulfate attacks. Adding fly ash (FA) in shotcrete mixtures enhanced the long-term performance but invited massive white efflorescence on surface layer under partial-immersion exposure condition. Silica fume (SF) admixture can compensate the undesired reduction of early-age strength caused by FA addition, but make these specimens more susceptible to sulfate attack. Mercury intrusion porosimetry (MIP) analysis, scanning electron microscopy (SEM), and X-ray diffraction (XRD) tests reveal that these consequences were strongly related to the refinement of microstructure resulted from pozzolanic reactions and hydration kinetics.

Lab and Field Study of Physical Sulfate Attack on Concrete Mixtures with Supplementary Cementitious Materials

2021 ◽  
Vol 33 (1) ◽  
pp. 04020397
Author(s):  
Mohammed H. Alyami ◽  
Hossein Mosavi ◽  
Raid S. Alrashidi ◽  
Mohammed A. Almarshoud ◽  
Christopher C. Ferraro ◽  
...  
Keyword(s):  
Field Study ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Supplementary Cementitious Materials ◽  
Concrete Mixtures

Properties of Mortar Incorporating Ground Dune Sand as Cement Replacement Material

2014 ◽  
Vol 925 ◽  
pp. 334-338
Author(s):  
Omer Abdalla Alawad ◽  
Abdulrahman Alhoziamy ◽  
Mohd Saleh Jaafar ◽  
Abdulaziz Al-Negheimish ◽  
Farah Noor Abdul Aziz
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Drying Shrinkage ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Supplementary Cementitious Materials ◽  
Replacement Level ◽  
Dune Sand ◽  
Cement Replacement ◽  
Autoclave Curing

Supplementary cementitious materials provide economic and environmental advantages in concrete industry. In this study, natural ground dune sand (GDS) was used as cement replacement material to fabricate mortar specimens. Ordinary Portland cement was replaced by GDS at five levels of replacement (0, 10, 20, 30, and 40 %) by weight. The cast mortar specimens were cured under normal and autoclave curing conditions. Compressive strength, drying shrinkage and resistance to sulfate attack were investigated. Results showed that the compressive strength under normal curing decreased as the level of replacement increased. However, under autoclave curing compressive strength increased as the content of GDS increased with 30% being the optimum replacement level. Autoclave curing decreased the drying shrinkage of plain and GDS blended mixtures by about 70% compared to control mixture cured under normal curing. Up to 270 days, no sulfate attack was observed on the GDS blended mixtures regardless of the replacement level. The use of GDS to reduce the Portland cement consumption can have a significant impact on the sustainability and economy of concrete construction.

scholarly journals The Resistance of Novel Concrete Prepared by Gap-Graded Blended Cement under Chloride-Sulfate Attack

2021 ◽  
Vol 2109 (1) ◽  
pp. 012024
Author(s):  
Yudong Han ◽  
Tongsheng Zhang ◽  
Yiqun Guo ◽  
Wenli Tian ◽  
Jiahao Li
Keyword(s):  
Cement Paste ◽  
Binding Capacity ◽  
Early Period ◽  
Blended Cement ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Supplementary Cementitious Materials ◽  
Cement Concrete ◽  
Chloride Sulfate ◽  
Functional Components

Abstract The resistance of concrete under chloride-sulfate attack dominates the durability of marine constructions. The binder played a more important role in chloride-sulfate resistance of concrete due to the dynamic hydration process. Incorporating supplementary cementitious materials (SCMs) was beneficial to the microstructure densification of cement paste, but the low hydraulic activities of SCMs resulted in the decrease of mechanical properties, activating activities of SCMs would raise the cracking risk of cement paste. On the basic of close packing theory, a gap-graded blended cement contained calcined hydrotalcite and metakaolin was adopted to prepare concrete with high resistance under chloride-sulfate attack in present study. The gap-graded blended cement concrete presented comparable strength with Portland cement concrete, even though only 25% clinker used in the blended cement. Because of the continuous hydration of alumina-rich SCMs and functional components, the secondary hydration products with high chloride binding capacity helped blocking ions ingress, resulting in the one-magnitude decrease of chloride diffusivity. At the early period of soaking duration in chloride-sulfate solution, the sulfate ions were beneficial to delaying the migration of chloride. And the cracks introduced by expansive products from sulfate attack would observably accelerate the release and continuous ingress of chloride at late period.

scholarly journals Evaluation of external sulfate attack (Na2SO4 and MgSO4): Portland cement mortars containing siliceous supplementary cementitious materials

2020 ◽  
Vol 13 (4) ◽  
Author(s):  
Diego Jesus de Souza ◽  
Marcelo Henrique Farias de Medeiros ◽  
Juarez Hoppe Filho
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Supplementary Cementitious Materials ◽  
Hardened Cement ◽  
X Ray Diffraction ◽  
Sulfate Ions ◽  
Cement Mortars ◽  
Physical And Chemical

ABSTRACT: Sulfate attack is a term used to describe a series of chemical reactions between sulfate ions and hydrated compounds of the hardened cement paste. The present study aims to evaluate the physical (linear expansion, flexural and compressive strength) and mineralogical properties (X-ray diffraction) of three different mortar compositions (Portland Cement CPV-ARI containing silica fume and rice husk ash, in both cases with 10% replacement of the cement by weight) against sodium and magnesium sulfate attack (concentration of SO42- equal to 0.7 molar). The data collected indicate that the replacing the cement by the two siliceous supplementary cementitious materials (SCMs) generate similar results, both SCMs were able to mitigate the effects of the sodium sulfate attack in both physical and chemical characteristics, however, both materials increase the deterioration (i.e. compressive strength) when exposed to MgSO4 solution.

Improving the sulfate attack resistance of concrete by using supplementary cementitious materials (SCMs): A review

2021 ◽  
Vol 281 ◽  
pp. 122628
Author(s):  
Md Manjur A Elahi ◽  
Christopher R. Shearer ◽  
Abu Naser Rashid Reza ◽  
Ashish Kumer Saha ◽  
Md Nabi Newaz Khan ◽  
...  
Keyword(s):  
Cementitious Materials ◽  
Sulfate Attack ◽  
Supplementary Cementitious Materials

Effect of ground granulated blast funrnace slag and fly ash on strength, permeability, and under-water abrasion of fine-grained concrete

2020 ◽  
Vol 71 (7) ◽  
pp. 775-788
Author(s):  
Quyet Truong Van ◽  
Sang Nguyen Thanh
Keyword(s):  
Fly Ash ◽  
Concrete Strength ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Chloride Permeability ◽  
Cement Replacement ◽  
Fine Grained ◽  
Granulated Blast Furnace Slag ◽  
Compressive Strength Test ◽  
Economic Ground

The utilisation of supplementary cementitious materials (SCMs) is widespread in the concrete industry because of the performance benefits and economic. Ground granulated blast furnace slag (GGBFS) and fly ash (FA) have been used as the SCMs in concrete for reducing the weight of cement and improving durability properties. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40% and 60% by weight were used in fine-grained concrete. The ternary binders containing GGBFS and FA at cement replacement ratio of 60% by weight have also evaluated. Flexural and compressive strength test, rapid chloride permeability test and under-water abrasion test were performed. Experimental results show that the increase in concrete strength with GGBFS contents from 20% to 40% but at a higher period of maturity (56 days and more). The chloride permeability the under-water abrasion reduced with the increasing cement replacement by GGBFS or a combination of GGBFS and FA

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