scholarly journals POROSITY, PERMEABILITY AND MICROSTRUCTURE OF FOAMED CONCRETE THROUGH SEM IMAGES

2019 ◽  
Vol 10 (1) ◽  
pp. 22-33 ◽  
Author(s):  
P. Shawnim ◽  
F. Mohammad
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Pore Size ◽  
High Porosity ◽  
Capillary Water ◽  
Sem Images ◽  
Microstructural Investigation ◽  
Capillary Water Absorption ◽  
Foamed Concrete ◽  
Percentage Ratio

This paper examined the foamed concrete (FC) for permeability of total and capillary water absorption, at 28 days of air sealed curing. The microstructure of 15 selected FC specimens was investigated to determine permeability in relation to porosity and density using Scanning Electron Microscopy (SEM) images. The FC specimens of the densities (1100, 1600, and 1800) kg/m3 were made using fine sand and brick aggregates with toner and MK inclusion as additives. The microstructural investigation of the FC revealed, porosity measure as a percentage ratio of the area under investigation to be in the range of (39.65 to 77.7) %. The pore size is in the range of (0.01 to 70) µm, depending on the type of additive, for the mixes containing toner and MK, it is in a fine range of (0.01 to 10.0) µm. For the FC specimens, the finer the pore size, the less permeable and the stronger it is. Permeability is porosity and strength dependent, whereby high porosity leads to high permeability and low compressive strength for FC mixes made with sand or brick only with no additive inclusion. Meanwhile, the FC mixes made with the inclusion of additives, such as the toner and MK20 mixes, showed an evenly spread net of independent air voids with a regular shape within their matrix, which is beneficial in decreasing permeability. Therefore, besides the porosity and strength, the fineness of the pore matrix and the shape factor of the pores are two other key factors in controlling permeability. Toner and MK20 inclusion can enhance the capillary water absorption to reach almost water tight. Besides, MK30 and MK50 inclusion displayed adverse effect on permeability. Depending on the type of filler, the additive, and the percentage ratio of the porosity of the FC matrix at (1600 and 1800) kg/m3 densities, it is possible to produce FC with compressive strength between (55.1 and 30) N/mm2.

scholarly journals Investigation of Thermal, Mechanical and Transport Properties of Ultra-Lightweight Foamed Concrete (ULFC) Strengthened with Alkali Treated Banana Fibre

2021 ◽  
Vol 86 (1) ◽  
pp. 123-139
Author(s):  
Mohammed Hassan Nensok ◽  
Md Azree Othuman Mydin ◽  
Hanizam Awang
Keyword(s):  
Compressive Strength ◽  
Thermal Properties ◽  
Water Absorption ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
High Porosity ◽  
Control Specimen ◽  
Sem Images ◽  
Banana Fibre

Traditionally, Ultralightweight Foam Concrete (ULFC) is primarily used to replace filling excavations, ditch restoration and underground channels, because of their high porosity, water absorption and low strength. Yet, ULFC is characterized by excellent thermal properties and could be an alternative for sustainable energy-efficient building material. This study investigates the properties of an ULFC strengthened with alkali-treated banana fibre. The low density ULFC of 600kg/m3 was fabricated and strengthened with alkali-treated banana fibre. Fibre volume fraction of 0.25%, 0.35%, 0.45% and 0.55% were compared to the unreinforced specimens, serving as the control specimen (no fibre addition). Mix proportioning of 1:1.5:0.45 of cement, sand, and water was respectively adopted throughout the mix. The alkali treated banana fibre strengthened ULFC was tested for compressive strength, sorptivity and thermal properties. Morphology of the treated fibre and ULFC composites was studied using SEM micrograph. The result depicts that ULFC exhibited the optimum compressive strength of 1.1604N/mm2 with the fibre volume fraction of 0.35%. Sorptivity or rate of water absorption was testified to upsurge, after 24 hours duration at fibre volume fraction of 0.55%, recording a 56.12% increment compared to the control specimen. The finding displays that at the highest-fibre volume fraction of 0.55%, thermal conductivity and diffusivity decrease by 13.17% and 28.16%, correspondingly, whiles the specific heat capacity increases to 37.17% all compared with unreinforced specimens. SEM images reveal that the presence of lumen and the nature of porous and fibrous alkali-treated banana fibre. Hence, it is endorsed that ULFC produced with alkali-treated banana fibre should be utilized as an infill material for composite system.

Influence of Morphology of Cathode-Ray Tube Glass as Coarse Aggregates on Compressive Strength and Water Absorption of Concrete

2018 ◽  
Vol 280 ◽  
pp. 399-409
Author(s):  
Nurul Noraziemah Mohd Pauzi ◽  
Maslina Jamil ◽  
Roszilah Hamid ◽  
Muhammad Fauzi Mohd Zain
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Coarse Aggregate ◽  
Capillary Water ◽  
Capillary Water Absorption ◽  
Coarse Aggregates ◽  
Concrete Properties ◽  
Concrete Production ◽  
Cathode Ray Tube ◽  
Texture Size

The study on the substitution for natural coarse aggregates using waste CRT funnel glass in spherically shapes is still limited. In this paper, the waste CRT glass has been processed to form a spherical CRT glass (GS) and crushed CRT glass (GC), which were used as a coarse aggregate in concrete production. Results indicated that the inclusion of GS and GC has lower the compressive strength and decreased the rate of capillary water absorption of concrete. It was demonstrated that the morphology properties of GS and GC (shape, surface texture, size, grading) is significantly affected the concrete properties.

3-Aminopropyl-Triethoxysilane Functionalized Graphene Oxide for Silane-Based Consolidation Treatments to Increase Mortar Performances

2021 ◽  
Vol 21 (4) ◽  
pp. 2351-2359
Author(s):  
C. Cadar ◽  
C. I. Fort ◽  
A. Mihis ◽  
Zs. Kedves ◽  
K. Magyari ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Graphene Oxide ◽  
Water Absorption ◽  
Untreated Control ◽  
Mechanical Tests ◽  
Capillary Absorption ◽  
Capillary Water ◽  
Functionalized Graphene Oxide ◽  
Capillary Water Absorption ◽  
Control Samples

The influence of chemically converted GO (graphene oxide) functionalized with APTES (3-aminopropyl-triethoxysilane) and unfunctionalized GO, dispersed in ethanolic solution of TEOS (tetraethyl orthosilicate), on the performances of the mortar samples, such as capillary water absorption and compressive strength was evaluated. The effect of the GO based nanomaterials (GO and GO functionalized with APTES) on the mortar microstructure was investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). The multifunctionality of the mortar brushed with GO based nanomaterials consolidation suspension was proved by the results (i) of the mechanical tests which show an improvement of the compressive strength and (ii) the capillary water absorption results which indicate the decreasing of the water penetration speed. For the mortar samples brushed with GO consolidation suspension, an increase value for the compressive strength of approximately twice compared to the untreated control samples and a decreased value for the capillary absorption water coefficient with one order of magnitude in comparison with the untreated control samples were obtained.

Use of polyvinyl chloride (PVC) powder and granules as aggregate replacement in concrete mixtures

2016 ◽  
Vol 23 (2) ◽  
pp. 209-216 ◽  
Author(s):  
Hakan Bolat ◽  
Pınar Erkus
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Water Absorption ◽  
Polyvinyl Chloride ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Capillary Water ◽  
Capillary Water Absorption ◽  
Concrete Mixtures ◽  
Compressive Strength Test

AbstractConcrete is one of the materials in which polymer wastes are utilized. Generally, these wastes are added at specific rates in scientific studies but an important problem of waste polymers is size irregularity. Even when consistent dosage rates are used, variations in polymer size can lead to variability in the physical and mechanical properties of the concrete produced. The aim of this study is to determine physical and mechanical properties of polyvinyl chloride (PVC)-containing concretes. In order to produce normal and high strength concretes, 10%, 20%, and 30% replacement ratios of PVC powder and granules by volume of aggregate are used. Slump, fresh and hardened densities, compressive strength, capillary water absorption, and abrasion were tested on all concrete types. As the PVC ratio increases, important changes are seen in all physical and mechanical concrete properties. The unit weights of the 10%, 20%, and 30% replacement PVC powder concretes are lower by ∼4%, 8%, and 13%, respectively, as compared to the reference mixtures, and the replacement PVC granule concretes are lower by ∼2%, 4%, and 7%. Compressive strength test results showed similar trends. As PVC replacement increases, the capillary water absorption decreases between 10% and 50%, and abrasion decreases between 27% and 77%.

scholarly journals Natural pozzolana addition effect on compressive strength and capillary water absorption of Mortar

2017 ◽  
Vol 139 ◽  
pp. 689-695 ◽  
Author(s):  
Walid Deboucha ◽  
Nordine Leklou ◽  
Abdelhafid Khelidj ◽  
Mohamed N. Oudjit
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Capillary Water ◽  
Capillary Water Absorption ◽  
Natural Pozzolana

scholarly journals Influence of Crystalline Admixtures on the Short-Term Behaviour of Mortars Exposed to Sulphuric Acid

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 82 ◽  
Author(s):  
Victoria García-Vera ◽  
Antonio Tenza-Abril ◽  
José Saval ◽  
Marcos Lanzón
Keyword(s):  
Compressive Strength ◽  
Absorption Coefficient ◽  
Water Absorption ◽  
Sulphuric Acid ◽  
Cementitious Materials ◽  
Pulse Velocity ◽  
Capillary Water ◽  
Short Term ◽  
Water Absorption Coefficient ◽  
Capillary Water Absorption

Using durable materials is a sustainable solution for extending the lifetime of constructions. The use of crystalline admixtures makes cementitious materials more durable. They plug pores, capillary tracts and microcracks, blocking the entrance of water due to the formation of crystals that prevent the penetration of liquids. The literature has covered the performance of these admixtures on concrete, but studies on mortars are still scarce. The aim of this study is to investigate the effect of an aggressive environment (sulphuric acid solution—3 wt%) on mortars produced with different percentages of a crystalline admixture (1%, 1.5% and 2% by weight of cement content). Physical and mechanical properties were studied after immersing the mortars in a H2SO4 solution for 90 days. It was found that, after a 90-day sulphuric acid exposure, mortars with the crystalline admixture showed greater compressive strength than the control mortar, besides exhibiting lower mass loss. However, the crystalline admixture did not produce any significant effect on the capillary water absorption coefficient. In a nonaggressive environment, and in the short term, the crystalline admixture did not have a significant effect on the compressive strength, the capillary water absorption coefficient or the ultrasonic pulse velocity.

scholarly journals Properties of Self-Compacting Mortar Containing Slag with Different Finenesses

2021 ◽  
Vol 7 (5) ◽  
pp. 840-856
Author(s):  
Said Kenai ◽  
Siham Hammat ◽  
Belkacem Menadi ◽  
Jamal Khatib ◽  
El-Hadj Kadri
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Yield Stress ◽  
Autogenous Shrinkage ◽  
The Other ◽  
Mineral Admixtures ◽  
Rheological Parameters ◽  
Capillary Water ◽  
Capillary Water Absorption ◽  
Slump Flow

It is well established that Self-Compacting Concrete (SCC) contains large amounts of fines including mineral admixtures, such as fly ash and slag, in order to avoid segregation and to increase cohesion. The use of these materials in concrete reduces CO2 emissions and contributes towards sustainable construction. To overcome the negative effect of slag on the strength development slag was ground to three finenesses. Therefore, this paper examines the rheological, compressive strength, total and autogenous shrinkage and capillary water absorption of Self-Compacting Mortars (SCM) containing ground granulated blast furnace Slag (S). A total of seven mortar mixes were prepared. The control mix had a proportion of 1 (cement): 1.8 (sand): 0.38 (water). In the other mixes, the cement was partially replaced with 15% and 30% slag of different fineness of 350, 420, and 500 m2/kg. The other constituents remained unchanged. Testing included slump flow, V-funnel flow time, yield stress and viscosity, compressive strength, total and autogenous shrinkage, and capillary water absorption. The presence of slag was found to reduce the plastic viscosity and yield stress of SCM mixtures as the content and the fineness increase. The higher the fineness (specific surface) of the slag the less the rheological parameters (i.e. slump flow and viscosity). The results show also a reduction in compressive strength of SCM at early ages of curing in the presence of slag. However, in the long-term, the compressive strength of SCM mixtures containing slag was higher than that of control mortar. Generally, there is reduction in the total shrinkage and an increase in the autogenous shrinkage of SCM mixtures as the content and fineness increase. Doi: 10.28991/cej-2021-03091694 Full Text: PDF

scholarly journals COMPRESSIVE STRENGTH OF FOAMED CONCRETE IN RELATION TO POROSITY USING SEM IMAGES

2019 ◽  
Vol 10 (1) ◽  
pp. 34-44
Author(s):  
Paybar Ali Shawnim ◽  
Fouad Mohammad
Keyword(s):  
Compressive Strength ◽  
Shape Factor ◽  
Fine Sand ◽  
High Porosity ◽  
Structural Elements ◽  
Pore System ◽  
Sem Images ◽  
High Compressive Strength ◽  
Foamed Concrete ◽  
Curing Method

Foamed concrete specimens were examined for compressive strength at (28 and 180) days air sealed curing, as well as at 28 days water cured. Also, the microstructure of fifteen selected FC specimens was investigated for porosity in relation to compressive strength using Scanning Electron Microscopy (SEM) images. Twenty two batches of FC specimens of the densities (1100, 1600 and 1800) kg/m3 were made with fine sand and brick aggregates with toner and metakaolin (MK) inclusion as additives, they were casted in polystyrene cube moulds of (100x100x100) mm. Results show, it is possible to produce FC with high compressive strength in the range of (28.5 to 59.2) N/mm2, with a variety of materials, while the 1600 kg/m3 density with the inclusion of toner and MK20 is the favourite, which can be used for structural elements. Conventionally, compressive strength is in an inverse relationship with porosity, as porosity increases, compressive strength decreases, but using toner and MK20 can alter this relationship between porosity and compressive strength, where by it is possible to produce a relatively light weight high porosity FC matrix to exhibit high compressive strength. Maturity of the FC at 180 days, can demonstrate an increase in the compressive strength. The microstructural investigations through SEM images revealed, the FC mix made with sand or brick only, exhibits an irregular shape factor of the micro pore system with the pore size in the range of (10 to 70) µm, while those made with the inclusion of toner and MK20 have a regular shape factor of a matrix of finer micro pore system of the sizes in the range of (0.01 to 10.0) µm, all of which are evenly distributed, and have a big influence on the properties of the FC, particularly, on compressive strength. Contrary to the conventional method of air sealed curing for FC, water curing method can equally give the same or a slightly better result in respect of compressive strength for some particular densities.

Simulieren der kapillaren Wasseraufnahme von porösen Werkstoffen des Bauwesens / Modelling of the Capillary Water Absorption of Porous Building Materials

2000 ◽  
Vol 6 (3) ◽  
pp. 293-306
Author(s):  
J. Elsen ◽  
F. de Barquin
Keyword(s):  
Water Absorption ◽  
Pore Size ◽  
Building Materials ◽  
Automated Image Analysis ◽  
Invasion Percolation ◽  
Capillary Water ◽  
Capillary Suction ◽  
Capillary Water Absorption ◽  
Porous Building Materials ◽  
3D Network

Abstract Profound knowledge of the moisture transport in porous building materials is essential to understand and to improve their durability. Water flow in these materials is mainly driven by capillary forces and the capillary suction of a porous building material depends on its pore structure. We have designed a statistical model to simulate the capillary water absorption of porous building materials based on invasion percolation rules. A 3D-network with 30x30x100 sites was used and the trapping effect is included. The input for the simulated invasion percolation is a pore size distribution obtained by a stereological analysis of the results of automated image analysis measurements on SEM-BSE-images of polished sections. Pore size distributions of nine different materials have been determined experimentally by SEM and by MIP. The simulated absorption curves agree reasonably well with the experimental absorption curves.

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