Functional properties of foam concrete with ultra-small additives of carbon nanotubes

2021 ◽  
Vol 1 ◽  
pp. 49-57
Author(s):  
R. D. Sldozyan ◽  
◽  
A. G. Tkachev ◽  
Z. A. Mikhaleva ◽  
A. E. Burakov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Bending Strength ◽  
Testing Machine ◽  
Control Sample ◽  
Strength Increase ◽  
Foam Concrete ◽  
High Concentrations

We studied the properties of foam concrete based on Portland cement, modified with of the ultra-low concentration carbon nanotubes addition. Carbon nanotubes (Taunit-24) with a mass percentage of 0.0004, 0.0006, 0.0008, 0.001 and 0.0012 % by weight of cement were used for the dispersed reinforcement of foam concrete based on Portland cement. To determine of the modified concrete samples strength characteristics an IP-M testing machine was used. The results of the study showed that the use of the carbon nanotubes additives in concentrations of 0.0004, 0.0006, 0.0008 % allows to gradually increase the compressive strength compared to the control sample. The compressive strength increase on 1, 12.4 and 68 %, respectively, and gradually decreases at concentrations of 0.001 and 0.0012 % from 55.5 to 45.7 %, respectively. A positive effect of the carbon nanotubes additive (0.0004, 0.0006 and 0.0008 %) is also noted when testing the bending strength by 3.7, 13.7 and 33.7%, respectively. With a further increase in the additive content (0.001 and 0.0012 %), the strength decreases to 20 and 14.8 %, respectively. When assessing water absorption, a decrease was showed with additives with concentrations of 0.0004 and 0.0006 %. However, at high concentrations of additives (0.0008, 0.001 and 0.0012 %), the highest percentage of water absorption was established.

Study on Waterproof and Water-Resistant Properties of Gypsum

2012 ◽  
Vol 476-478 ◽  
pp. 1585-1588
Author(s):  
Hong Pan ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Ordinary Portland Cement ◽  
Experimental Results ◽  
Softening Coefficient

The comprehensively modified effect of cement, VAE emulsion and self-made acrylic varnish on mechanical and water-resistant properties of gypsum sample was investigated and microstructure of gypsum sample was analyzed. Experimental results exhibit that absolutely dry flexural strength, absolutely dry compressive strength, water absorption and softening coefficient of gypsum specimen with admixture of 10% ordinary Portland cement and 6% VAE emulsion and acrylic varnish coated on its surface can respectively reach to 5.11MPa , 10.49 MPa, 8.32% and 0.63, respectively.

scholarly journals The Effect of Nano Metakaolin Material on Some Properties of Concrete

2013 ◽  
Vol 6 (1) ◽  
pp. 50-61
Author(s):  
Amer M. Ibrahem ◽  
Shakir A. Al-Mishhadani ◽  
Zeinab H.Naji
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Thermal Activation ◽  
Ordinary Portland Cement ◽  
Splitting Tensile Strength ◽  
Kaolin Clay ◽  
Cement Ratio ◽  
Water Cement Ratio

This investigation aimed to study the effect of nano metakaolin ( NMK ) on some properties (compressive strength ,splitting tensile strength & water absorption ) of concrete. The nano metakaolin (NMK) was prepared by thermal activation of kaolin clay for 2 hours at 750 Ċ. The cement used in this investigation consists of ordinary Portland cement (OPC). The OPC was partially substituted by NMK of ( 3, 5 & 10%) by weight of cement. The C45 concrete was prepared , using water/cement ratio ( W/c) of (0.53) .The Water absorption was tested at 28 days while the tests (compressive strength ,splitting tensile strength) were tested at ages of (7, 28, 60,& 90) days . The compressive strength and splitting tensile strength of concrete with NMK were higher than that of reference concrete with the same W/c ratio.The improvement in the compressive strength when using NMK was (42.2, 55.8 , 63.1% ) at age 28 days for ( 3%, 5%, &10% ) replacement of NMK respectively whereas the improvement in the splitting tensile strength was (0% , 36% & 46.8 %) at age of 28 days when using (3%, 5%, &10% ) NMK respectively. The improvement in the water absorption was (16.6%, 21.79%, &25.6 ) when using (3, 5, &10% )NMK.

scholarly journals Biofuel Combustion Fly Ash Influence on the Properties of Concrete

2016 ◽  
Vol 7 (5) ◽  
pp. 546-550
Author(s):  
Aurelijus Daugėla ◽  
Džigita Nagrockienė ◽  
Laurynas Zarauskas
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Water Absorption ◽  
Frost Resistance ◽  
Ash Content ◽  
Mineral Admixtures ◽  
Binding Agent ◽  
Materials Used ◽  
Plasticizing Admixture

Cement as the binding agent in the production of concrete can be replaced with active mineral admixtures. Biofuel combustion fly ash is one of such admixtures. Materials used for the study: Portland cement CEM I 42.5 R, sand of 0/4 fraction, gravel of 4/16 fraction, biofuel fly ash, superplasticizer, water. Six compositions of concrete were designed by replacing 0%, 5%, 10%, 15% 20%, and 25% of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the properties of concrete. The tests revealed that the increase of biofuel fly ash content up to 20% increases concrete density and compressive strength after 7 and 28 days of curing and decreases water absorption, with corrected water content by using plasticizing admixture. It was found that concrete where 20% of cement is replaced by biofuel ash has higher frost resistance.

scholarly journals Influences of shrinkage reducing admixture on the mechanical properties, drying shrinkage, water absorption and porosity of Portland cement mortar

2021 ◽  
Vol 15 (3) ◽  
pp. 55-67
Author(s):  
Nguyen Van Chinh
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Drying Shrinkage ◽  
Effective Porosity ◽  
Minor Effect ◽  
Wide Range ◽  
Shrinkage Reducing Admixture ◽  
A Minor

Drying shrinkage is the main cause of early age cracking of concrete and mortar. A wide range of research has been conducted to reduce the drying shrinkage, including using fibres or chemical admixtures. This paper investigated the effect of shrinkage reducing admixture on the flexural strength, compressive strength, drying shrinkage, water absorption and porosity of mortar. The mix compositions were ordinary Portland cement (OPC) : sand : liquid = 1: 1: 0.38 in which liquid consisted of water and shrinkage reducing admixture (SRA). SRA was used at the proportions of 2%, 4%, and 7% by weight of cement. The test results show that SRA reduces the flexural and compressive strengths of mortar. The reduction in flexural strength and compressive strength at 28 days is 14% and 25%, respectively at 7% SRA dosage. In addition, SRA significantly reduces the drying shrinkage and water absorption of mortar. At 7% SRA dosage, the drying shrinkage at 53 days is reduced by 60% while the water absorption rate at 24 hours is reduced by 54%. However, SRA has a minor effect on the pore size distribution, effective porosity, and cumulative intrusion volume of mortar.

Study of Coconut Charcoal Powder and Egg Shell Powder as Partial Replacement to Fine Aggregates and Cement in Load Bearing Concrete Bricks

2020 ◽  
Vol 853 ◽  
pp. 120-125
Author(s):  
Airvin John C. Palacio ◽  
Nioro G. Furiscal ◽  
Katrina Mae L. Abalos ◽  
Dioven Angelo A. Alferez ◽  
Edmer A. Bade ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Construction Materials ◽  
Control Sample ◽  
Agricultural Wastes ◽  
Partial Replacement ◽  
Agriculture Sector ◽  
Coconut Charcoal ◽  
Fine Aggregates ◽  
Egg Shell

Waste disposal is one of the issues that plague the society. Philippines is an agricultural country due to its strategic location in the tropics. Because of this nature, the agriculture sector tends to produce a huge amount of waste that if not disposed properly could pose a threat to the society and to the environment. With the advancement of technology, it has been a challenge for researchers to improve the quality of construction materials that is used in the industry. Studies have been performed on the possibilities of incorporating agricultural wastes to various construction materials as a form of waste diversion. In order to address the problem with agricultural wastes as well as to improve the property of construction materials, a study on coconut waste and eggshell waste was conducted as a constituent in concrete brick production. In this study, the density, compressive strength as well as the water absorption of concrete bricks with coconut charcoal powder (CCP) and eggshell powder (ESP) as replacement for fine aggregates and cement was conducted. Different mix ratios (0%, 2.5%, 5%, 10% CCP with a constant value of 5% ESP in each mix ratio) were carried out and the results were compared to a control sample. From the results of the density test, the concrete bricks with 5% CCP and 5% ESP was the lightest at a density of 1678.184 kg/m3, it also showed the least water absorption at 8.58% and exhibited the highest compressive strength at 17.5 MPa.

scholarly journals Hydrochloric Acid Pretreatment of Different Types of Rice Husk Ash Influence on the Properties of Cement Paste

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1524 ◽  
Author(s):  
Jing Liu ◽  
Chunyan Xie ◽  
Chao Fu ◽  
Xiuli Wei ◽  
Dake Wu
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Cement Paste ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Control Sample ◽  
Control Group ◽  
Rice Husks ◽  
Acid Pretreatment ◽  
Blank Control Group

When properly processed, rice husk ash (RHA) comprises a large amount of SiO2, which exhibits a high pozzolanic activity and acts as a good building filler. In this paper, the effects of rice husk ash content, acid pretreatment, and production regions on the compressive and flexural properties and water absorption of a cement paste were studied. The experimental results showed that the compressive strength of the rice husk ash was the highest with a 10% content level, which was about 16.22% higher than that of the control sample. The rice husk after acid pretreatment displayed a higher strength than that of the sample without the acid treatment, and the rice husk from the Inner Mongolia region indicated a higher strength than that from the Guangdong province. However, the flexural strength of each group was not significantly different from that of the blank control group. The trend observed for the water absorption was similar to that of the compressive strength. The variation in the RHA proportions had the greatest influence on the properties of the paste specimens, followed by the acid pretreatments of the rice husks. The production regions of the rice husks indicated the least influence.

scholarly journals Recycling of waste incineration bottom ash in the production of interlocking concrete bricks

2021 ◽  
Vol 15 (2) ◽  
pp. 101-112
Author(s):  
Nguyen Huu May ◽  
Huynh Trong Phuoc ◽  
Le Thanh Phieu ◽  
Ngo Van Anh ◽  
Chau Minh Khai ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Bending Strength ◽  
Bottom Ash ◽  
Waste Incineration ◽  
Engineering Properties ◽  
Fine Aggregate ◽  
Test Results ◽  
Toxic Material ◽  
Visible Defect

This study presents an experimental investigation on the recycling of waste incineration bottom ash (IBA) as a fine aggregate in the production of interlocking concrete bricks (ICB). Before being used, the concentration of heavy metal in IBA was determined to confirm it is a non-toxic material. In this study, the IBA was used to replace crushed sand (CSA) in the brick mixtures at different replacement levels of 0%, 25%, 50%, 75%, and 100% (by volume). The ICB samples were checked for dimensions, visible defects, compressive strength, bending strength, water absorption, and surface abrasion in accordance with the related Vietnamese standards. The test results demonstrated that the IBA used in this study was a non-toxic material, which can be widely used for construction activities. All of the ICB samples prepared for this study exhibited a nice shape with consistent dimensions and without any visible defects. The incorporation of IBA in the brick mixtures affected engineering properties of the ICB samples such as a reduction in the compressive strength and bending strength and an increment in water absorption and surface abrasion of the brick samples. As a result, the compressive strength, bending strength, water absorption, and surface abrasion values of ICB samples at 28 days were in the ranges of 20.6 – 34.9 MPa, 3.95 – 6.62 MPa, 3.8 – 7.2%, and 0.132 – 0.187 g/cm2, respectively. Therefore, either partial or full replacement of CSA by IBA, the ICB with grades of M200 – M300 could be produced with satisfying the TCVN 6476:1999 standard in terms of dimensions, visible defects, compressive strength, water absorption, and surface abrasion. These results demonstrated the high applicability of the local IBA in the production of the ICB for various construction application purposes. Keywords: interlocking concrete brick; waste incineration bottom ash; visible defect; compressive strength; bending strength; water absorption; surface abrasion.

scholarly journals Mechanical Properties of OPC - Geocement Concrete

2019 ◽  
Vol 8 (4) ◽  
pp. 3733-3736
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
External Heat ◽  
Partial Replacement ◽  
Strength Development ◽  
Strength Increase ◽  
Heat Curing ◽  
Compressive Strength Development

Nowadays geopolymer concretes are subjected to heat curing. A large amount of highly corrosive and the hygroscopic alkaline activators are nowadays generally utilized in producing geopolymer concretes. In this paper, hybrid Ordinary Portland Cement (OPC) and geopolymer mixes are developed. The mainly used activator id the Solid potassium carbonate at different percentage is used as 5% & 10% of the weight of geopolymeric materials and OPC was blended with geopolymeric materials in different proportions. By adding cement, improves all the geopolymer properties except workability. By Applying external heat, it plays an important role in gaining strength. Strength gained by the absence of external heat is achieved by using Portland cement as a partial replacement of geocement. The influence of OPC content on the compressive strength development is investigated, and the optimized amount of solid activator to be used in the mix is also investigated. It is observed that percentage of strength increase decreases from52.24% to 14.77% as the OPC content increased from 20% to 60%.

A brief description of the foam concrete: its properties, advantages and disadvantages: review

2020 ◽  
Vol 10 ◽  
Author(s):  
Ruqaya F. Hamada ◽  
Awham M. Hameed
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Energy Saving ◽  
Weight Ratio ◽  
Current Work ◽  
Foam Concrete ◽  
Conventional Concrete ◽  
Advantages And Disadvantages ◽  
Foamed Concrete

: The foam concrete has many advantages when compared to conventional concrete such as advanced strength to weight ratio as well as the material for energy-saving construction. This concrete has broadly been utilized in the constructing manufacturing. The current work presents an appraisal of foamed concrete ingredients, fabricating methods, as well as the foamed concrete features. Furthermore, this literature appraisal aims for providing a complete vision about the tests, including compressive strength, density, porosity, splitting tensile strength and water absorption of foamed concrete. Also, this paper focuses to study the development and applications of the foam concrete. The advantages and disadvantages of this type of concrete were presented in details through this article.

Alkali Activated Binders Based on Metakaolin

2015 ◽  
Vol 1 ◽  
pp. 200
Author(s):  
Laura Sele ◽  
Diana Bajare ◽  
Girts Bumanis ◽  
Laura Dembovska
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Raw Materials ◽  
Sodium Silicate Solution ◽  
Total Porosity ◽  
Lead Silicate ◽  
Cement Production ◽  
Alkali Activated Binders ◽  
Alkali Activated

<p>According to research conducted in last 25 years, alkali activated binders have been considered as one of the most progressive alternative binders, which can effectively replace Portland cement. Production of alkali activated binders differs from the Portland cement production and is associated with lower CO2 emissions. The use of recycled industrial by-products and wastes is also possible, what corresponds to the future guidelines and principles of sustainable binder production in the world.<br />The aim of this study was to create innovative alkali activated binders by using secondary raw materials, which will be different from the ones described in the scientific literature – alkali activated binders with porous structure. Raw materials used for the binders were metakaolin containing waste, waste from aluminium scrap recycling factory and recycled lead-silicate glass; solid contents were activated with modified sodium silicate solution with an addition of sodium hydroxide.<br />The physical properties of alkali activated binders, such as density, water absorption, open and total porosity, were determined and flexural and compressive strength of hardened alkali-activated binders were tested at the age of 28 days. Durability was examined by sulphate resistance test, which was performed according to SIA 262/1, appendix D: applicability and relevance for use in practice. 40x40x160 mm prismatic specimens were used for expansion measurement and determination of compressive strength. <br />The open porosity of obtained materials was up to 45%, density from 380 to 1720 kg/m3, compressive strength up to 29,8 MPa, water absorption 6 – 114 wt.%. After analysing the results from the sulphate test it was concluded that glass additive reduced the alkali activated binder resistance to sulphate attack.</p>

Sign in / Sign up

Export Citation Format

Share Document