Microstructural Features and Mechanical Properties of Autoclaved Saline Soil Brick: Part II: Mechanical Properties

2012 ◽  
Vol 510 ◽  
pp. 655-659
Author(s):  
Lie Qu ◽  
Jiu Jun Yang ◽  
Shou Xi Chai ◽  
Lei Guo ◽  
Su Li
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Hydrothermal Reaction ◽  
Saline Soil ◽  
Reaction Products ◽  
Quartz Powder ◽  
Water Binding ◽  
Binding Ratio ◽  
Compressive And Flexural Strengths ◽  
Optimal Material

The effects of different components, autoclaving temperature and time on the mechanical properties of saline soil bricks were investigated. The autoclaved curing schedule is optimized at autoclaving time of 3h and autoclaving temperature of 175. The optimal material formula consists of water-binding ratio 0.2, CaO 15%, finely grinded quartz powder 20 % and sand 20%, under which the compressive and flexural strengths of saline soil bricks reaches 31.9 Mpa and 7.8Mpa, respectively. Reducing water-binding ratio will effectively promote density, while increasing the amount of CaO will enhance the hydrothermal reaction products, density and the mechanical strength. In addition, adding finely grinded quartz powder and sand will further increase the hydrothermal reaction products and restrict volume shrinkage. Furthermore, elevating autoclaving temperature and extending autoclaving time are favorable to increase density and to improve mechanical properties. But autoclaving time exceeds 3h, the compressive strength will be reduced.

scholarly journals Microstructural and Mechanical Properties of Alkali Activated Materials from Two Types of Blast Furnace Slags

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2089 ◽  
Author(s):  
Jun Xing ◽  
Yingliang Zhao ◽  
Jingping Qiu ◽  
Xiaogang Sun
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Thermal Stabilization ◽  
Hydration Process ◽  
Reaction Products ◽  
Basic Oxide ◽  
X Ray ◽  
Physical And Chemical ◽  
Alkali Activated

This paper investigated the effect of blast furnace slags (BFS) characteristics on the properties achievement after being alkali activated. The physical and chemical characteristics of BFS were determined by X-ray fluorescence (XRF), X-ray Diffraction (XRD) and laser granulometry. Multi-technical characterizations using calorimetry, XRD, Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetry (TG-DTG), scanning electron microscope (SEM), nitrogen sorption and uniaxial compressive strength (UCS) were applied to give an in-depth understanding of the relationship between the reaction products, microstructure and BFS characteristics. The test results show that the microstructure and mechanical properties of alkali activated blast furnace slags (BFS) highly depend on the characteristics of BFS. Although the higher content of basic oxide could accelerate the hydration process and result in higher mechanical properties, a poor thermal stabilization was observed. On the other hand, with a higher content of Fe, the hydration process in alkali activated BFS2 lasts for a longer time, contributing to a delayed compressive strength achievement.

Effect of volcanic tuff on the engineering properties of compressed earth block

2020 ◽  
Vol 1 (106) ◽  
pp. 5-16
Author(s):  
W.F. Edris ◽  
Y. Jaradat ◽  
A.O. Al Azzam ◽  
H.M. Al Naji ◽  
S.A. Abuzmero
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Engineering Properties ◽  
Volcanic Tuff ◽  
Point Of Interest ◽  
Compressed Earth Block ◽  
New Material ◽  
Compressive And Flexural Strengths ◽  
Earth Block ◽  
Future Work

Purpose: of this paper is to investigate the durability and the mechanical properties, including compressive and flexural strengths, of the locally compressed earth blocks manufactured from soil in Irbid, Jordan. Moreover, effect of volcanic tuff as new stabilizer material on properties of compressed earth block (CEB). Compressed earth block is a technique that was created to solve environmental and economic problems in construction sector. It is widespread in many countries around the world but hasn't been used in Jordan yet. Design/methodology/approach: 9 mixtures were carried out. One of this mixture is the control mix, beside other mixtures were performed by replacing soil with 40%, 10%, 10%, of sand, volcanic tuff, and lime respectively. In addition, polypropylene fibre was used. After 28 days of curing, the CEB were dried in oven at 105ºC for 24 hours then tested. Findings: Show that absorption and erosion were decreased when the lime used in the soil. On the other hand, the fibres presence significantly improved the durability and mechanical properties in all mixtures. Moreover, the higher compressive strength was obtained in the mixtures which contain lime only while the higher tensile strength was obtained in the mixtures which contain lime with sand replacement. The using of volcanic tuffs produced average compressive strength values. The reason is that in the presence of lime and pozzolana (volcanic tuff) reactions take place at low and slow rate at early ages. Research limitations/implications: volcanic tuff can produce favourable compressive strengths at later ages and this is a point of interest in the future work. Originality/value: Searching for a new material as stabilizer material that improves the properties of the compressed earth block (CEB).

Effect of Activator Concentration on the Properties of Metakaolin-Based Geopolymer

2019 ◽  
Vol 11 (11) ◽  
pp. 1566-1573
Author(s):  
Chao Cui ◽  
Zhen Liu ◽  
Jianren Zhang ◽  
Chunsheng Cai ◽  
Hui Peng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Energy Dispersive Spectrometer ◽  
Curing Temperature ◽  
Activator Concentration ◽  
Reaction Products ◽  
Sem Images ◽  
Homogeneous Matrix ◽  
Ft Ir ◽  
Alkaline Activator

In the present study, an alkaline solution, prepared by sodium silicate (Na2SiO3) and sodium hydroxide (NaOH), was used as an activator for the preparation of a metakaolin-based geopolymer with high compressive strength. The effects of the factors, including the modulus (SiO2/Na2O ratio) of the alkaline activator, activator concentration, curing temperature, and curing time on the mechanical properties of the geopolymer were examined using orthogonal tests. Test results showed that the concentration of the alkaline activator is the primary factor affecting the mechanical properties of the geopolymer, followed by the modulus of the alkaline activator. The compressive strength of the geopolymer increases with an increase in activator concentration and decrease in the modulus of the alkaline activator. Subsequently, the reaction degree of the geopolymer and the reaction products corresponding to various concentrations of the activator were investigated using microcalorimetric analysis, Fourier Transform Infrared (FT-IR) analysis, and Scanning electron microscopy-Energy Dispersive Spectrometer (SEM-EDS) analysis, and the mechanism of the activator concentration affecting the geopolymer properties was also studied. It was found that the hydrolysis reaction and the polymerization degree were improved with an increase in the activator concentration. When the activator concentration increased from 50% to 80%, the compressive strength of the geopolymer increased from 21.54 MPa to 99.89 MPa. In addition, the SEM images also showed that the reaction products with a higher activator concentration, had a denser and more homogeneous matrix than that of products with a lower activator concentration.

scholarly journals Performance of Carbon Fiber Filament Reinforcing Cement Mortar

2021 ◽  
Vol 7 (10) ◽  
pp. 1693-1701
Author(s):  
Ahmed Hamed El-Sayed Salama ◽  
Walid Fouad Edris
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Cement Mortar ◽  
Physical And Mechanical Properties ◽  
Experimental Program ◽  
Flow Table ◽  
Compressive And Flexural Strengths ◽  
Measured Density

This paper aims to study the effect of Carbon Fiber Filament (CFF) with different ratios and lengths on the physical and mechanical properties of cement mortar. An experimental program included 3 cm fixed length of CFF with 0, 0.25, 0.5, 0.75, and 1% different ratios by weight of cement addition were used in cement mortar cubes. Another experimental program of 0.5% CFF ratio with 1, 2, 3, 4, and 5 cm different lengths by weight of cement addition was used in cement mortar prisms. The physical and mechanical properties of cement mortar containing CFF were experimentally investigated at 7 and 28 days of curing. Workability, by means of flow table test, were measured. Density is conducted for cubes and prisms at the age of 28 days. At ages of 7 and 28 days, compressive and flexural strengths were studied. The study showed a reduction in workability with the increase of CFF ratios and lengths by 0.0 to 2.7% and by 0.9 to 5.4% respectively. Moreover, an improvement in density, compressive, and flexural strengths was observed. At ages of 7 and 28 days, the results showed that compressive strength increased by 33 and 31% respectively at 0.5% of CFF ratio while the flexural strength increased by 125 and 327% respectively with CFF length of 5 cm. Doi: 10.28991/cej-2021-03091753 Full Text: PDF

scholarly journals EXPERIMENTAL STUDY ON THE MECHANICAL BEHAVIOUR OF FIRED SAND-CLAY AND GLASS POWDER-CLAY BRICKS

2021 ◽  
Vol 27 (1) ◽  
pp. 4-10
Author(s):  
Adeolu Adediran ◽  
Abayomi Akinwande ◽  
Oluwatosin Balogun ◽  
Olanrewaju Adesina ◽  
Adeniyi Olayanju
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Mechanical Behaviour ◽  
Glass Powder ◽  
Flexural Modulus ◽  
Fine Sand ◽  
Clay Bricks ◽  
Waste Glass Powder ◽  
Fired Bricks ◽  
Compressive And Flexural Strengths

Mechanical behaviour of fired bricks containing varied amount of fine sand (FS) and waste glass powder (GP) was investigated. FS and GP were added to bricks at varied amount of 0, 5, 10, 15, 20, 25, 30, 35 and 40 wt. %. Firing was done at 1200 ⁰C and samples produced were evaluated for compressive and flexural strengths while microstructural analyses of 25 wt. % FS and GP-clay bricks were examined. Results showed that compressive strength was highest at 30 wt. % GP for GP-bricks while for FS-clay bricks, compressive strength rose to 35 and 40 wt. % FS addition.  Flexural strength for GP-clay and FS-clay bricks peaked at 30 wt. % GP (3.63 MPa) and 40 wt % FS (2.45) respectively. Flexural modulus increased progressively and exponentially as FS and GP proportion increased. Workdone in resisting deformation and deflection during bending reduced with increased amount of both additives. Flexural strain was inversely related to load and stiffness. In conclusion, addition of GP and FS in increasing amount resulted in improved mechanical properties in the bricks. Also, increased proportion of GP and FS was found to improve response to loading in fired bricks.

scholarly journals Mechanical properties and permeability of red mud-blast furnace slag-based geopolymer concrete

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Xiangzhou Liang ◽  
Yongsheng Ji
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Red Mud ◽  
Blast Furnace Slag ◽  
Construction Materials ◽  
Geopolymer Concrete ◽  
Reaction Products ◽  
Alumina Production ◽  
Furnace Slag

AbstractRed mud, a by-product of alumina production, has a great impact on the environment due to its high alkalinity. In this paper, two-part geopolymer mortar was synthesized by combining red mud and blast furnace slag (BFS) to obtain optimized compressive strength and flexural strength for construction materials. Geopolymer concrete was prepared with the cementitious material in the concrete replaced by geopolymer mortar. Mechanical properties, permeability and microscopic properties of geopolymer concrete were measured. The results showed that the compressive strength grade of concrete prepared with geopolymer concrete can reach 54.43 MPa indicating that the geopolymer concrete can be used as materials for load-bearing members in structures. Due to lower total porosity and better pore structure, the permeability resistance of geopolymer concrete was significantly better than ordinary concrete. Microscopic analysis indicated that a large amount of aluminosilicate reaction products was generated in a geopolymer by the reaction of OH− with the aluminosilicate components in red mud and BFS in a strongly alkaline environment. The surface [SiO4]4− and [AlO4]4− tetrahedrons form chemical bonds through dehydroxylation, which is the direct reason for their high strength and determines their excellent physical and chemical properties.

scholarly journals Compressive and Flexural Strengths of Concrete Containing Ground Palm Kernel Shells as Partial Replacement of Cement

2020 ◽  
Vol 7 (1) ◽  
pp. 7-16
Author(s):  
Esau Abekah Armah ◽  
Hubert Azoda Koffi ◽  
Josef K Ametefe Amuzu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Cylindrical Specimen ◽  
Palm Kernel ◽  
Test Method ◽  
Partial Replacement ◽  
Optimum Level ◽  
Compressive And Flexural Strengths ◽  
Palm Kernel Shells

This study explore the possibility of using waste ground palm kernel (GPK) shells as partial replacement of cement in concrete using mechanical destructive method has been studied. The palm kernel shells were in two forms: the GPK ordinary shells and shells subjected to incomplete combustion (i.e. the GPK “fuel” shells. In the preparation of the concrete specimens the mix ratio was 1: 2: 4 (cement: sand: stone) by weight and The replacement percentage was 0%, 20%, 30%, 40%, 50% and 60% respectively.  Concrete specimen were molded in both cubic and cylindrical form and its impact on the mechanical properties such as workability, compressive strength and flexural strength using destructive test method were studied. The cubic specimen were tested at 7, 28 and 60 days whiles the cylindrical specimen were tested at 7 and 28 days. Results of physical and chemical analyses suggest that GPK “fuel” shells have acceptable cementitious properties whiles GPK ordinary shells does not. Generally, the compressive and flexural strengths of concrete containing GPK shells decrease as the replacement percentage increases. However, the values of these properties increase as the period of curing increases. The optimum level of GPK shells replacement is 20% for the ordinary shells and 30% for the “fuel” shells considering compressive strength at 28 days for the cubic samples. For the flexural strength on the cylindrical specimen, up to 60% replacement of cement by GPK shells cured for 28 days has acceptable flexural strength. In spite of the findings that the GPK ordinary shells do not have cementitious properties, the mechanical properties on such concretes can be used in low strength constructions as pavements, walk ways and non structural domestic work at a lower cost than using cement.

The Influence of Curing Conditions on the Physical and Mechanical Properties of Magnesia Phosphate Cements

2008 ◽  
Vol 59 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Jenica Paceagiu ◽  
Maria Georgescu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Variable Temperature ◽  
Physical And Mechanical Properties ◽  
Reaction Products ◽  
Phosphate Binding ◽  
Curing Conditions ◽  
Weight Variation ◽  
Chemical Solutions

The paper brings information on the influence of curing conditions such as humidity, variable temperature and chemical solutions, on the compressive strength and weight variation of the magnesia phosphate binding materials, obtained from magnesite, mono-ammonia phosphate, borax and sand having a granulation ranging between 0.1-1 mm, with or without fly ash addition. The XRD and SEM�EDX analysis were made for obtaining information concerning the reaction products formed in phosphate magnesia binding materials cured in conditions of variable humidity.

Properties of Environmental Friendly Concrete Containing Recycled Coarse Aggregate and Fly Ash

2013 ◽  
Vol 368-370 ◽  
pp. 957-962
Author(s):  
Xiao Shuang Shi ◽  
Qing Yuan Wand ◽  
Lang Li ◽  
Tao Long
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Recycled Concrete ◽  
Reaction Products ◽  
X Ray ◽  
Transition Zones ◽  
Environmental Friendly ◽  
Scanning Electron

Six mixtures with different ratios (0%, 50% and 100%) were designed to investigate the compressive strength, elastic modulus and Poissons ratio of geopolymeric recycled concrete (GRC). The mechanical properties and failure mechanism of recycled concrete (RAC) and GRC were tested and discussed by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX). The results show that, GRC concretes are stronger than RAC concretes due to different reaction products and better microstructure in interfacial transition zones (ITZs). The EDX results show that the higher compressive strength with higher Si/Al ratio.

Microstructural and fractographic characterization of B4C-Al cermets tested under dynamic and static loading

1989 ◽  
Vol 47 ◽  
pp. 562-563
Author(s):  
Gyeung Ho Kim ◽  
Mehmet Sarikaya ◽  
D. L. Milius ◽  
I. A. Aksay
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Static Loading ◽  
Carbon Deposition ◽  
Full Density ◽  
Unique Combination ◽  
Strong Component ◽  
Reaction Products

Cermets are designed to optimize the mechanical properties of ceramics (hard and strong component) and metals (ductile and tough component) into one system. However, the processing of such systems is a problem in obtaining fully dense composite without deleterious reaction products. In the lightweight (2.65 g/cc) B4C-Al cermet, many of the processing problems have been circumvented. It is now possible to process fully dense B4C-Al cermet with tailored microstructures and achieve unique combination of mechanical properties (fracture strength of over 600 MPa and fracture toughness of 12 MPa-m1/2). In this paper, microstructure and fractography of B4C-Al cermets, tested under dynamic and static loading conditions, are described.The cermet is prepared by infiltration of Al at 1150°C into partially sintered B4C compact under vacuum to full density. Fracture surface replicas were prepared by using cellulose acetate and thin-film carbon deposition. Samples were observed with a Philips 3000 at 100 kV.

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