Mechanical Behaviors and Frost-Resistance of Alkali Activated Cement Concrete with Different Binder Systems

Mapping Intimacies ◽

10.20944/preprints202012.0747.v1 ◽

2020 ◽

Author(s):

Biruk Hailu Tekle ◽

Klaus Holschemacher ◽

Philipp Löber ◽

Björn Heiden

Keyword(s):

Flexural Strength ◽

Greenhouse Gas Emission ◽

Construction Material ◽

Source Material ◽

Conventional Concrete ◽

Freeze Thaw ◽

Strength And Durability ◽

Source Materials ◽

Alkali Activated ◽

Alkali Activated Cement

Concrete is the most commonly used construction material due to its various advantages, such as versatility, familiarity, strength and durability and it will continue to be in demand far into the future. However, with today’s sensitivity to the environmental protection, this material is facing unprecedented challenges due to its high greenhouse gas emission mainly during cement production. This paper investigates one of the promising cement replacement materials, alkali activated cement (AAC) concrete. Being produced mainly from byproduct materials and having a comparable structural performance to conventional concrete, AAC concrete has a potential to transform the construction industry. Mechanical properties such as compressive and flexural strength and the relationship between them are studied. Different source materials such as fly ash (FA), ground granulated blast furnace slag (GGBS), silica fume (SF) and Metakaolin (MK) are used. The effect of the source materials and the activator solutions on the concrete performance is studied. Furthermore, the freeze-thaw resistance of the concrete is studied. The results of the study showed that the behavior of AAC depends highly on the source material combinations as well as type used. The effect of the alkaline solution is also dependent on the source material used. Mixes with higher GGBS content in general showed the highest strength while mixes with MK showed the highest flexural strength. The results from the freeze-thaw test showed that proper design of AAC concrete with a lower water content is critical to achieve a good resistance.

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Mechanical Behavior and Frost-Resistance of Alkali-Activated Cement Concrete with Blended Binder at Ambient Curing Condition

Buildings ◽

10.3390/buildings11020052 ◽

2021 ◽

Vol 11 (2) ◽

pp. 52

Author(s):

Biruk Hailu Tekle ◽

Klaus Holschemacher ◽

Philipp Löber ◽

Björn Heiden

Keyword(s):

Flexural Strength ◽

Construction Material ◽

Source Material ◽

Conventional Concrete ◽

Freeze Thaw ◽

Study Results ◽

Strength And Durability ◽

Source Materials ◽

Alkali Activated ◽

Alkali Activated Cement

Concrete is the most commonly used construction material because of its various advantages, such as versatility, familiarity, strength, and durability, and it will continue to be in demand far into the future. However, with today’s sensitivity to environmental protection, this material faces unprecedented challenges because of its high greenhouse gas emissions, mainly during cement production. This paper investigates one of the promising cement replacement materials, alkali-activated cement (AAC) concrete. Being produced mainly from byproduct materials and having a comparable structural performance to conventional concrete, AAC concrete can transform the construction industry. Mechanical properties such as compressive and flexural strength and the relationship between them are studied. Different source materials such as fly ash (FA), ground granulated blast furnace slag (GGBS), silica fume (SF), and Metakaolin (MK) are used. The effect of the source materials and the activator solutions on the concrete performance is studied. Furthermore, the freeze-thaw resistance of the concrete is studied. The study results showed that the behavior of AAC depends highly on the source material combinations and type used. The effect of the alkaline solution is also dependent on the source material used. Mixes with higher GGBS content showed the highest strength, while mixes with MK showed the highest flexural strength. The freeze-thaw test results showed that proper design of AAC concrete with lower water content is critical to achieving a good resistance.

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Performance of Modified Rubber Aggregate Concrete with GGBS and Silica

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.b7007.129219 ◽

2019 ◽

Vol 9 (2) ◽

pp. 2438-2441

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Flexural Strength ◽

Coarse Aggregate ◽

Research Programme ◽

Conventional Concrete ◽

Aggregate Concrete ◽

Waste Rubber ◽

Strength And Durability ◽

Micro Silica

Transfer of tyre rubber suit a tremendous difficulty in India step by step. Analysts are attempting to utilize waste rubber in structural building venture from numerous days back. When coarse aggregate was replaced with 20% chipped rubber it was found that the optimum replacement is5% but still there is a deficit in some strength from conventional concrete. This research programme tries to minimise this gap by adding extra 5% micro silica of the weight of cement and also by replacing 40% of cement by GGBS. Here cubes, cylinders, and prisms were casted to test compressive strength, tensile strength, flexural strength, and durability against heat and were observed after 28 days and 56 days

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Fracture Parameters of Fly Ash and GGBS Based Geopolymer Concrete

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.764-765.1090 ◽

2015 ◽

Vol 764-765 ◽

pp. 1090-1094

Author(s):

Tippabhotla D. Gunneswara Rao ◽

P. Alfrite ◽

G. Mallikarjuna Rao ◽

Mudimby Andal

Keyword(s):

Fly Ash ◽

Construction Material ◽

Bending Test ◽

Geopolymer Concrete ◽

Test Results ◽

Conventional Concrete ◽

Three Point Bending ◽

Beam Depth ◽

New Construction ◽

Source Materials

Geopolymer concrete (GPC) is a new construction material in which cement is totally replaced by calcined source materials fly ash and GGBS. Geopolymer utilization reduces or eliminates the use of cement whose production produces a lot of carbon dioxide. Usually fly ash as a source material for the geopolymer. The behavior of GPC has to be studied in detail to check its suitability in construction industry. In the present study, the fracture behavior of geopolymer concrete is investigated and compared. Three-point bending test on notched prisms with a/d (notch depth/beam depth) ratios 0.1, 0.15, 0.2 are considered. The values of Critical load, fracture toughness, fracture energy and ductility are presented. The test results of total of 27prisms, 6cubes, 18 cylinders with M30 grade geopolymer concrete and conventional concrete (OPC) of same grade are presented in this paper. The test results indicated that the characteristic length of GPC is about 25% more than that of conventional concrete.

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Estudio de la resistencia a compresión del hormigón utilizando el vidrio finamente molido en reemplazo parcial del cemento

Revista de Investigaciones en Energía Medio Ambiente y Tecnología RIEMAT ISSN 2588-0721 ◽

10.33936/riemat.v4i2.2187 ◽

2020 ◽

Vol 4 (2) ◽

pp. 1

Author(s):

Sophía Moncerrat Alvarado Mera ◽

Andy Gabriel Vélez Soledispa ◽

Wilter Enrique Ruiz Párraga ◽

Eduardo Humberto Ortiz Hernández ◽

César Mauricio Jarre Castro

Keyword(s):

Compressive Strength ◽

Raw Materials ◽

Construction Material ◽

Sustainable Construction ◽

Ground Glass ◽

Partial Replacement ◽

Conventional Concrete ◽

Renewable Raw Materials ◽

Test Pieces ◽

Strength And Durability

El hormigón obtenido a partir de vidrio finamente molido es una línea de investigación a nuevos materiales, basados en el ahorro del cemento y a su vez en la disminución del dióxido de carbono a la atmósfera para obtener un material constructivo más eficiente y sostenible. Con el propósito de buscar una solución para la fabricación de hormigones, la utilización del vidrio finamente molido como reemplazo parcial del cemento es una de las alternativas para integrarlo al proceso constructivo, cuyo objetivo es disminuir el empleo de materias primas no renovables, utilizando materiales reciclados con excelentes características de resistencia y durabilidad. En la presente investigación se estudió la resistencia a compresión del hormigón, usando vidrio finamente molido, sustituyéndolo en porcentajes del 5%, 10% y 15% en reemplazo parcial del cemento. Se elaboraron probetas de hormigón convencional y probetas de hormigón con adición de vidrio finamente molido, a cada probeta experimentada se le realizó el ensayo de resistencia a compresión del hormigón en un tiempo máximo de curado húmedo de 56 días. Se realizó la comparación entre el hormigón sin adición y el hormigón con porcentajes de vidrio finamente molido, llegando a la conclusión que el vidrio sustituido al 15% como reemplazo parcial del cemento disminuye su resistencia a compresión. Palabras claves — vidrio finamente molido, resistencia a compresión, hormigón, adición, cemento. Abstract The concrete obtained from finely ground glass is a line of investigation to new materials, based on the saving of cement and in turn on the reduction of carbon dioxide to the atmosphere to obtain a more efficient and sustainable construction material. In order to find a solution for the manufacture of concrete, the use of finely ground glass as a partial replacement of cement is one of the alternatives to integrate it into the construction process, whose aim is to reduce the use of non-renewable raw materials, using recycled materials with excellent strength and durability characteristics. In this research, the compressive strength of concrete was studied, using finely ground glass, replacing it in percentages of 5%, 10% and 15% in partial replacement of cement. Conventional concrete test pieces and concrete test pieces with the addition of finely ground glass were produced and each tested test piece was tested for the compressive strength of the concrete within a maximum curing time of 56 days A comparison was made between aggregate concrete and concrete with finely ground glass percentages, concluding that glass replaced at 15% as a partial replacement for cement decreases its compressive strength. Index Terms — finely ground glass, compressive strength, concrete, addition, cement.

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Durability Of Advanced Cement-Based Materials Used As Repairs For Deteriorated Concrete

10.32920/ryerson.14646327.v1 ◽

2021 ◽

Author(s):

Keikhosrow Tahmureszadeh

Keyword(s):

Bond Strength ◽

High Performance Concrete ◽

Construction Material ◽

Advanced Technology ◽

Repair System ◽

Freeze Thaw ◽

Thaw Cycle ◽

Cement Based Materials ◽

Strength And Durability ◽

Durability Performance

With advanced technology, the production of strong construction material becomes more feasible. However, use of such materials as repairs on top of existing concrete is challenging, since repair system relies not only on the quality of repair but also on the interaction and compatibility of such material with the substrate. Studies regarding the durability of bond strength are limited. Therefore, the objective of this research is to compare the bond strength and durability performance of advanced cement-based materials including ultra-high performance concrete (UHPC), engineered cementitious composite with slag (ECC-Slag), specialized repair material with self-consolidating properties (SCC), and normal concrete (NC) under two common deterioration modes in Canada (freeze-thaw cycles with de-icing salt, and volumetric expansion of the substrate). The freeze-thaw cycle results show higher bond strength and durability performance for UHPC and NC, respectively. Under expanding deterioration, NC started with higher bond strength and UHPC revealed the best durability performance.

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Durability Of Advanced Cement-Based Materials Used As Repairs For Deteriorated Concrete

10.32920/ryerson.14646327 ◽

2021 ◽

Author(s):

Keikhosrow Tahmureszadeh

Keyword(s):

Bond Strength ◽

High Performance Concrete ◽

Construction Material ◽

Advanced Technology ◽

Repair System ◽

Freeze Thaw ◽

Thaw Cycle ◽

Cement Based Materials ◽

Strength And Durability ◽

Durability Performance

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Documents and Source Material

Journal of Palestine Studies ◽

10.1525/jps.2017.47.1.s5 ◽

2017 ◽

Vol 47 (1) ◽

pp. 1-7

Keyword(s):

Human Rights ◽

Source Material ◽

Human Rights Abuses ◽

Palestinian Territories ◽

Source Materials ◽

Israeli Occupation

This section comprises JPS summaries and links to international, Arab, Israeli, and U.S. documents and source materials from the quarter spanning 16 May-15 November 2017. Fifty years of Israeli occupation was the focus of reports by the UN Office for the Coordination of Humanitarian Affairs (OCHA) and Oxfam that documented the ongoing human rights abuses in the occupied Palestinian territories. Other notable documents include Israeli NGO Gisha and UNSCO reports on the ten-year Gaza siege, Al Jazeera's interactive timeline of the Nakba, and an exchange of letters between the ACLU and U.S. senators on anti-BDS legislation.

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Oral Testimony as Historical Source Material for the Reconstruction of the Judicial History of Shipping in India (1600-1800)

Oral History Journal of South Africa ◽

10.25159/2309-5792/3618 ◽

2019 ◽

Vol 7 (1) ◽

Author(s):

Mir Kamruzzman Chowdhary

Keyword(s):

Nineteenth Century ◽

Source Material ◽

Maritime History ◽

Historical Source ◽

Alternative Source ◽

Oral Testimony ◽

History Of ◽

Judicial History ◽

Source Materials

This study was an attempt to understand how the available alternative source materials, such as oral testimonies can serve as valuable assets to unveiling certain aspects of maritime history in India. A number of themes in maritime history in India failed to get the attention of the generation of historians, because of the paucity of written documents. Unlike in Europe, the penning down of shipping activities was not a concern for the authorities at the port in India. The pamphlets and newsletters declared the scheduled departure of the ship in Europe but, in India, this was done verbally. Therefore, maritime history in India remained marginalised. Hence, in this article, I make an endeavour to perceive how the oral testimonies can help shed some new light on certain aspects of maritime history in India, such as life on the ship, maritime practices, and perceptions among the littoral people in coastal societies. This article also outlines an approach on how the broader question on the transformation of scattered maritime practices among coastal societies can be adapted and transferred into an organised institution of law by the nineteenth century, and how these can be pursued in future. I also suggest in this article that the role of Europeans, especially the British, in the process of transformation, can be investigated further through oral testimonies in corroboration with the colonial archival records.

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Effect of Recycled Coarse Aggregate and Bagasse Ash on Two-Stage Concrete

Crystals ◽

10.3390/cryst11050556 ◽

2021 ◽

Vol 11 (5) ◽

pp. 556

Author(s):

Muhammad Faisal Javed ◽

Afaq Ahmad Durrani ◽

Sardar Kashif Ur Rehman ◽

Fahid Aslam ◽

Hisham Alabduljabbar ◽

...

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Coarse Aggregate ◽

Construction Material ◽

Strength Reduction ◽

Recycled Aggregate ◽

Two Stage ◽

Conventional Concrete ◽

Recycled Coarse Aggregate ◽

Coarse Aggregates

Numerous research studies have been conducted to improve the weak properties of recycled aggregate as a construction material over the last few decades. In two-stage concrete (TSC), coarse aggregates are placed in formwork, and then grout is injected with high pressure to fill up the voids between the coarse aggregates. In this experimental research, TSC was made with 100% recycled coarse aggregate (RCA). Ten percent and twenty percent bagasse ash was used as a fractional substitution of cement along with the RCA. Conventional concrete with 100% natural coarse aggregate (NCA) and 100% RCA was made to determine compressive strength only. Compressive strength reduction in the TSC was 14.36% when 100% RCA was used. Tensile strength in the TSC decreased when 100% RCA was used. The increase in compressive strength was 8.47% when 20% bagasse ash was used compared to the TSC mix that had 100% RCA. The compressive strength of the TSC at 250 °C was also determined to find the reduction in strength at high temperature. Moreover, the compressive and tensile strength of the TSC that had RCA was improved by the addition of bagasse ash.

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