Effect of Various Additives and Aeration on the Properties of Lightweight Concrete

2018 ◽  
Vol 762 ◽  
pp. 351-355 ◽  
Author(s):  
Genadijs Sahmenko ◽  
Eva Namsone ◽  
Kristaps Rubenis ◽  
Arita Dubnika ◽  
Guntars Niparts
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Silica Fume ◽  
Bending Strength ◽  
Lightweight Concrete ◽  
Silica Sand

In the present study the effect of various additives (silica sand, silica fume, zeolite and cenospheres) as well as the aeration on the properties (consistency, density, compressive and bending strength) of lightweight concrete was studied. Density, compressive and bending strength of the lightweight concrete were substantially reduced by replacing silica sand with censopheres or by adding air entraining agent to the grout used for the preparation of the samples. Silica fume and zeolite admixture improved mechanical properties of the samples. Specific compressive strength of the cenospheres containing samples is comparable or even higher than the ones made of the mixes without the cenospheres.

scholarly journals The Effect of Borax Solution as Preservative to the Mechanical Properties of Bamboo

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
M.A.P Handana ◽  
◽  
Besman Surbakti ◽  
Rahmi Karolina ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Bending Strength ◽  
Environmentally Friendly ◽  
Preservative Solution ◽  
Borax Solution ◽  
Preservative Solutions

The use of borax solution as a preservative in wood and bamboo materials is well known in the community. A borax solution is an environmentally friendly liquid that can dissolve in water, so it is suitable to be used as a preservative within cold or hot soaking techniques. The ability of borax to resist insects and fungus attacks on bamboo has been proven, but the effect of the solution on the strength of bamboo must also be investigated. This study conducts to investigate the effects of borax and its additives as preservative solutions to the mechanical properties of bamboos. The bamboos preservations were conducted by cold conditions of immersion, while the mechanical properties were performed to understand the effects of preservatives. The result of this study indicated that 30% to 50% borax in the preservative solution is sufficient to provide significant increase in strength for compressive strength, tensile strength, and bending strength of bamboo specimen. From this study, the use of borax solution in preserving the bamboos materials improved the quality of bamboos based on its mechanical properties.

scholarly journals Strength Characteristics of High Strength Concrete (HSC) with and without Coarse Aggregate

2019 ◽  
Vol 9 (2) ◽  
pp. 4701-4704
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Mechanical Characteristics ◽  
Coarse Aggregate ◽  
High Strength ◽  
Set Up

This paper aimed to investigate the mechanical characteristics of HSC of M60 concrete adding 25% of fly ash to cement and sand and percentage variations of silica fumes 0%,5% and 10% to cement with varying sizes of 10mm,6mm,2mm and powder of granite aggregate with w/c of 0.32. Specimens are tested for compressive strength using 10cm X 10cmX10cm cubes for 7,14,28 days flexural strength was determined by using 10cmX10cmX50cm beam specimens at 28 days and 15cm diameter and 30cm height cylinder specimens at 28 days using super plasticizers of conplast 430 as a water reducing agent. In this paper the experimental set up is made to study the mechanical properties of HSC with and without coarse aggregate with varying sizes as 10mm, 6mm, 2mm and powder. Similarly, the effect of silica fume on HSC by varying its percentages as 0%, 5% and 10% in the mix studied. For all mixes 25% extra fly ash has been added for cement and sand.

scholarly journals Effects on Mechanical Properties of Recycled PET in Cement-Based Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Liliana Ávila Córdoba ◽  
Gonzalo Martínez-Barrera ◽  
Carlos Barrera Díaz ◽  
Fernando Ureña Nuñez ◽  
Alejandro Loza Yañez
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Compressive Strength ◽  
Compressive Strain ◽  
Young Modulus ◽  
Silica Sand ◽  
Chemical Compositions ◽  
Particle Sizes ◽  
Recycled Pet ◽  
Scanning Electron

Concretes consisting of portland cement (OPC), silica sand, gravel, water, and recycled PET particles were developed. Specimens without PET particles were prepared for comparison. Curing times, PET particle sizes, and aggregate concentrations were varied. The compressive strength, compressive strain at yield point, and Young modulus were determined. Morphological and chemical compositions of recycled PET particles were seen in a scanning electron microscopy. Results show that smaller PET particle sizes in lower concentrations generate improvements on compressive strength and strain, and Young’s modulus decreases when the size of PET particles used was increased.

scholarly journals Effect of fibre type and content on performance of bio-based concrete containing heat-treated apricot shell

2020 ◽  
Vol 53 (6) ◽  
Author(s):  
Fan Wu ◽  
Qingliang Yu ◽  
Changwu Liu ◽  
H. J. H. Brouwers ◽  
Linfeng Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Magnesium Sulfate ◽  
Fibre Type ◽  
Lightweight Concrete ◽  
Sulfate Attack ◽  
Fibre Glass ◽  
Heat Treated ◽  
Apricot Shell

AbstractThe heat-treated apricot shell can be utilized as coarse aggregates for producing sustainable bio-based lightweight concrete with good compressive strength but poor tensile strength. In order to improve the tensile properties of apricot shell concrete (ASC), the effects of polypropylene (PP) fibre, glass (G) fibre and basalt (B) fibre at various volume fractions (Vf) (0.25%, 0.5% and 0.75%) on the performance of ASC were investigated. The results indicated that the fibre type had no significant effect on the physical properties of ASC such as slump, density, water absorption and permeable porosity. However, the slump of ASC decreases with an increase in fibre content. The B fibre has a better improvement in mechanical properties than the PP fibre and G fibre thanks to the better elastic modulus and tensile strength. When the Vf was 0.5%, the compressive strength, splitting tensile strength, flexural strength and modulus of elasticity of ASC reinforced with B fibre were increased by 16.7%, 29.1%, 29.2%, and 18.1%, respectively, compared to ASC without any fibres. The magnesium sulfate attack results showed that the incorporation of the B fibre decreased the mass loss and compressive strength of ASC exposed to a MgSO4 solution for 6 months because the fibre arrested the microcracks caused by the expansive stress. It is concluded that the mechanical properties of bio-based ASC and its resistance to magnesium sulfate attack can be significantly improved by incorporating 0.5% B fibre.

scholarly journals Prediction Models for the Mechanical Properties of Self-Compacting Concrete with Recycled Rubber and Silica Fume

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1821 ◽  
Author(s):  
Robert Bušić ◽  
Mirta Benšić ◽  
Ivana Miličević ◽  
Kristina Strukar
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Silica Fume ◽  
Prediction Models ◽  
Crumb Rubber ◽  
Fine Aggregate ◽  
Rubberized Concrete ◽  
Self Compacting Concrete ◽  
Recycled Rubber ◽  
European Standards

The paper aims to investigate the influence of waste tire rubber and silica fume on the fresh and hardened properties of self-compacting concrete (SCC) and to design multivariate regression models for the prediction of the mechanical properties of self-compacting rubberized concrete (SCRC). For this purpose, 21 concrete mixtures were designed. Crumb rubber derived from end-of-life tires (grain size 0.5–3.5 mm) was replaced fine aggregate by 0%, 5%, 10%, 15%, 20%, 25%, and 30% of total aggregate volume. Silica fume was replaced cement by 0%, 5%, and 10% of the total cement mass. The optimal replacement level of both materials was investigated in relation to the values of the fresh properties and mechanical properties of self-compacting concrete. Tests on fresh and hardened self-compacting concrete were performed according to the relevant European standards. Furthermore, models for predicting the values of the compressive strength, modulus of elasticity, and flexural strength of SCRC were designed and verified with the experimental results of 12 other studies. According to the obtained results, mixtures with up to 15% of recycled rubber and 5% of silica fume, with 28 days compressive strength above 30 MPa, were found to be optimal mixtures for the potential future investigation of reinforced self-compacting rubberized concrete structural elements.

scholarly journals THE DEPENDENCE OF THE PHYSICAL MECHANICAL PROPERTIES OF EXPANDED-CLAY LIGHTWEIGHT CONCRETE ON THE COMPOSITION

2010 ◽  
Vol 2 (6) ◽  
pp. 50-55
Author(s):  
Marija Vaičienė ◽  
Jurgita Malaiškienė
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Chemical Composition ◽  
Water Absorption ◽  
Lightweight Concrete ◽  
Physical And Mechanical Properties ◽  
Concrete Mixture ◽  
Active Filler ◽  
Binder Material ◽  
Substitute Materials

Binder material is the most expensive raw component of concrete; thus, scientists are looking for cheaper substitute materials. This paper shows that when manufacturing, a part of the binder material of expanded-clay lightweight concrete can be replaced with active filler. The conducted studies show that technogenic – catalyst waste could act as similar filler. The study also includes the dependence of the physical and mechanical properties of expanded-clay lightweight concrete on the concrete mixture and the chemical composition of the samples obtained. Different formation and composition mixtures of expanded-clay lightweight concrete were chosen to determine the properties of physical-mechanical properties such as density, water absorption and compressive strength.

MECHANICAL PROPERTIES OF FLY ASH-BASED ALKALI-ACTIVATED CEMENT USING A STATISTICAL ANALYSIS TECHNIQUE

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Hyuk Lee ◽  
Vanissorn Vimonsatit
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Statistical Analysis ◽  
Fly Ash ◽  
Silica Fume ◽  
Dry Density ◽  
Analysis Method ◽  
Solid Ratio ◽  
Alkali Activated ◽  
Alkali Activated Cement

This paper presents the mechanical properties of fly ash-based alkali-activated cement (AAC). A statistical analysis method was used to determine the effect of mix proportion parameters on the dry density and compressive strength of fly ash-based AAC pastes and mortars. For that purpose, sample mixtures were designed according to Taguchi’s experimental design method, i.e., in a L9 orthogonal array. Four factors were selected: “silica fume content” (SF), “sand to solid ratio” (s/c), “liquid to solid ratio” (l/s), and “superplasticiser content” (SP). The experimental results were analysed by using signal to noise for quality control of each mixture, and analysis of variance (ANOVA) was used to determine the significant effect on the compressive strength of fly ash-based AAC. Furthermore, a regression-analysis method was used to predict the compressive strength according to the variation of the four factors. Results indicated that silica fume is the most influencing parameter on compressive strength, which could be decreased by superplasticiser and l/s ratio. There is no significant effect of sand-to-cementitious ratio on compressive strength of fly ash-based AAC. The dry density decreases as the sand-to-cementitious ratio is decreased. The increasing l/s ratio and superplasticiser dosage could further decrease the dry density of fly ash-based AAC.

Effect of steel slag powder, fly ash, and silica fume on the mechanical properties and durability of cement mortar

2019 ◽  
Vol 9 (9) ◽  
pp. 1049-1054
Author(s):  
Yunxia Lun ◽  
Fangfang Zheng
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cement Mortar ◽  
Steel Slag ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Slag Powder ◽  
Steel Slag Powder

This study is aimed at exploring the effect of steel slag powder (SSP), fly ash (FA), and silica fume (SF) on the mechanical properties and durability of cement mortar. SSP, SF, and FA were used as partial replacement of the Ordinary Portland cement (OPC). It was showed that the compressive and bending strength of steel slag powder were slightly lower than that of OPC. An increase in the SSP content caused a decrease in strength. However, the growth rate of compressive strength of SSP2 (20% replacement by the weight of OPC) at the curing ages of 90 days was about 8% higher than that of OPC, and the durability of SSP2 was better than that of OPC. The combination of mineral admixtures improved the later strength, water impermeability, and sulfate resistance compared with OPC and SSP2. The compressive strength of SSPFA (SSP and SF) at 90 days reached 70.3 MPa. The results of X-ray diffraction patterns and scanning electron microscopy indicated that SSP played a synergistic role with FA or SF to improve the performance of cement mortar.

The Influence of Aggregates on the Properties of Concrete

2014 ◽  
Vol 1000 ◽  
pp. 277-280 ◽  
Author(s):  
Pavel Šiler ◽  
Ondřej Bezděk ◽  
Iva Kolářová ◽  
Eva Bartoníčková ◽  
Tomáš Opravil ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Particle Size Analysis ◽  
Hydration Process ◽  
Silica Sand ◽  
Size Analysis ◽  
Isoperibolic Calorimetry

This work is focused on the influence of aggregates on the mechanical properties of concrete and hydration process. The flexural strength and compressive strength were observed after 1, 7 and 28 days of curing. The process of hydration was monitored using isoperibolic calorimetry. Laser particle size analysis of aggregates was also performed. The following materials were used: Portland cement CEM I 42,5 R-Sc, finely ground silica sand, calcinated bauxite, fine, medium and rough testing sand (defined in ČSN EN 196-1).

Physical and mechanical characteristics of cement mortars and concretes with addition of clinoptilolite from Beli Plast deposit (Bulgaria), silica fume and fly ash

Clay Minerals ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 213-223 ◽  
Author(s):  
V. Lilkov ◽  
I. Rostovsky ◽  
O. Petrov
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Specific Pore Volume ◽  
Cement Mortars ◽  
Physical And Mechanical Characteristics

AbstractCement mortars and concretes incorporating clinoptilolite, silica fume and fly ash were investigated for changes in their physical and mechanical properties. It was found that additions of 10% clinoptilolite and 10% Pozzolite (1:1 mixture of silica fume and fly ash) were optimal for improvement of the quality of the hardened products, giving 8% and 13% increases in flexural and compressive strength respectively. The specific pore volume of the mortars incorporating zeolite decreased between the 28th and 180th day to levels below the values for the control composition due to the fact that clinoptilolite exhibits its pozzolanic activity later in the hydration. In these later stages, pores with radii below 500 nm increased at the expense of larger pores. The change in the pore-size distribution between the first and sixth months of hydration occurs mostly in the mortars with added zeolite.

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