scholarly journals Studies on the effects of superficial strengthening with FRCM system on compressive strength of AAC masonry

2020 ◽  
Vol 19 (3) ◽  
pp. 022-032
Author(s):  
Łukasz Drobiec ◽  
Wojciech Mazur ◽  
Remigiusz Jokiel
Keyword(s):  
Compressive Strength ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete

This paper describes results from studies on the effects of superficial strengthening with FRCM system on compressive strength of autoclaved aerated concrete (AAC) masonry. Tests were carried out on models without any strengthening, strengthened at one or both sides. Two-side strengthened masonry demonstrated an increased compressive strength and deformability. Increased deformability was observed for one-side strengthened masonry when compared to tests on masonry without any strengthening.

Study on Production of Autoclaved Aerated Concrete by Coal Gangue Fly Ash

2013 ◽  
Vol 357-360 ◽  
pp. 949-954
Author(s):  
Ye Zhang ◽  
Peng Xuan Duan ◽  
Bao Sheng Jia ◽  
Lei Li
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Drying Shrinkage ◽  
Coal Gangue ◽  
National Standards ◽  
Raw Material ◽  
Autoclaved Aerated Concrete ◽  
Binder Ratio ◽  
Material Formulation ◽  
Aerated Concrete

In this paper, the low-silicon coal gangue fly ash is used to produce autoclaved aerated concrete. The influences of water binder ratio, coal gangue fly ash content, calcareous content and conditioning agents on the compressive strength of the autoclaved aerated concrete are investigated. Optimal raw material formulation and procedure are determined for the autoclaved aerated concrete. The compressive strength and frost resistance of autoclaved aerated concrete made by the optimal raw material formulation and procedure meet with the requirements of autoclaved aerated concretes of B05 grade, and its thermal conductivity, drying shrinkage reach the requirements of the relevant national standards of China.

scholarly journals Validation of Selected Non-Destructive Methods for Determining the Compressive Strength of Masonry Units Made of Autoclaved Aerated Concrete

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 389 ◽  
Author(s):  
Radosław Jasiński ◽  
Łukasz Drobiec ◽  
Wojciech Mazur
Keyword(s):  
Compressive Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
P Wave ◽  
In Situ Tests ◽  
Transmission Method ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Non Destructive

Minor-destructive (MDT) and non-destructive (NDT) techniques are not commonly used for masonry as they are complex and difficult to perform. This paper describes validation of the following methods: semi-non-destructive, non-destructive, and ultrasonic technique for autoclaved aerated concrete (AAC). The subject of this study covers the compressive strength of AAC test elements with declared various density classes of: 400, 500, 600, and 700 (kg/m3), at various moisture levels. Empirical data including the shape and size of specimens, were established from tests on 494 cylindrical and cuboid specimens, and standard cube specimens 100 mm × 100 mm × 100 mm using the general relationship for ordinary concrete (Neville’s curve). The effect of moisture on AAC was taken into account while determining the strength fBw for 127 standard specimens tested at different levels of water content (w = 100%, 67%, 33%, 23%, and 10%). Defined empirical relations were suitable to correct the compressive strength of dry specimens. For 91 specimens 100 mm × 100 mm × 100 mm, the P-wave velocity cp was tested with the transmission method using the ultrasonic pulse velocity method with exponential transducers. The curve (fBw–cp) for determining the compressive strength of AAC elements with any moisture level (fBw) was established. The developed methods turned out to be statistically significant and can be successfully applied during in-situ tests. Semi-non-destructive testing can be used independently, whereas the non-destructive technique can be only applied when the developed curve fbw–cp is scaled.

Effects of specimen dimensions and shape on compressive strength of specific autoclaved aerated concrete

ce/papers ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 541-556 ◽  
Author(s):  
Wojciech Mazur ◽  
Łukasz Drobiec ◽  
Radosław Jasiński
Keyword(s):  
Compressive Strength ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete

Effect Bonding Strength Steel Reinforcement with Epoxy Coating on the Character Destruction of Autoclaved Aerated Concrete Beams in Bending

2019 ◽  
Vol 974 ◽  
pp. 665-671
Author(s):  
Omar Ismael Alhashimi ◽  
AL-Hasnawi Yasser Sami Ghareb
Keyword(s):  
Compressive Strength ◽  
Bond Strength ◽  
Shear Failure ◽  
Lightweight Concrete ◽  
Construction Material ◽  
Reinforced Concrete Beam ◽  
Reinforcing Steel ◽  
Deep Beams ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete

Many of the complex reinforced Autoclaved Aerated Concrete characteristics under shear and flexure are yet to be identified to employ this material advantageously and economically, as it has many advantages of low weight, fire resistance, acoustic and thermal insulation. It is observed in the article that under two-points loading system, diagonal cracks are usually the first cracks to be observed in the deep beam clear span. The diagonal cracks first are developed in relatively deep beams and the flexural cracks are first developed in shallower beam. The principal mode of failure in the deep beams having adequate reinforcement is diagonal tension cracking. The shear failure is a common type for all beams. This indicates a weak the bond strength between lightweight concrete and reinforcing steel. There are many factors affecting the bond strength between the lightweight concrete and reinforcing steel, where the compressive strength plays an important role in bond strength, and the bond strength is increased by increasing the compressive strength. The AAC beams have the potential to be an excellently energy-saving construction material and is believed to emerge as an alternative to traditional reinforced concrete beam in the near future. This is proved by the experimental analysis.

scholarly journals Behaviour of Autoclaved Aerated Concrete Blocks using Alkali-Resistant Glass Fibre as Additive

2020 ◽  
Vol 8 (6) ◽  
pp. 3508-3513
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Glass Fibre ◽  
Physical And Mechanical Properties ◽  
Slight Variation ◽  
Average Value ◽  
Autoclaved Aerated Concrete ◽  
Concrete Blocks ◽  
Aerated Concrete ◽  
Masonry Units

Autoclaved aerated concrete (AAC) blocks are the lightweight and green concrete blocks that are composed of cement, fly ash, lime, gypsum and aluminium powder. Depending on its density AAC consists of up to 80% of air by volume. Due to their low density and lightweight Autoclaved aerated concrete blocks exhibit so many favourable physical properties that these have got attention from all around the globe. Due to these enhanced properties Autoclaved aerated concrete blocks are extensively used as masonry units in all types of construction. On one hand AAC blocks have no comparison with other types of masonry units in terms of physical properties but on other hand AAC blocks are found to have low compressive strength relatively. In this study an attempt has been made to study the influence of Alkali-Resistant Glass Fibre additive on the physical and mechanical properties of Autoclaved aerated concrete blocks. Four sets of samples were cast and named as A, B, C and D with the fibre additive contents as 0%, 0.1%, 0.2% and 0.3% respectively (by dry weight of all the ingredients).Each sample set consisted of three specimens and the average value of the three samples were taken. For example, the average value of the three specimens- A1 , A2 , and A3 was taken as A and so on. Fibre additive influenced the aeration process of Autoclaved aerated concrete by increasing the rising/aeration time by 8%. The investigated fibre additive increases the compressive strength by 0%, 10%, 24% and 13.8% respectively to the added fibre contents of 0%, 0.1%, 0.2%, and 0.3% respectively. The optimal content of Alkali-Resistant Glass Fibre additive to be added for obtaining the highest compressive strength is 0.2%. Further investigations have shown a slight variation in density (about 0.2%) between the normal and modified Autoclaved aerated concrete blocks.

Improving Mechanical Properties of Autoclaved Aerated Concrete by Sugar Sediment

2013 ◽  
Vol 807-809 ◽  
pp. 1266-1269 ◽  
Author(s):  
Atthakorn Thongtha ◽  
Somchai Maneewan ◽  
Chantana Punlek ◽  
Yothin Ungkoon
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Crystalline Morphology ◽  
X Ray Diffraction ◽  
Quality Class ◽  
X Ray ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Scanning Electron

The comparison of microstructure and mechanical properties between the autoclaved aerated concrete (AAC) and the autoclaved aerated concrete consist of sugar sediment (AAC-SS) was investigated in this work. The microstructure of AAC and AAC-SS was analyzed by the scanning electron microscopy (SEM). The mechanical properties of AAC and AAC-SS were focused on the compressive strength, the density, the water absorption and the flexural strength. To comfirm the tobermorite phase, the phase formation of the samples was tested using X-ray diffraction (XRD). It was found that the microstructure of AAC and AAC-SS surface was the finer needle-like crystalline morphology. The compressive strength (5.9 N/mm2) and flexural strength (1.82 N/mm2) of AAC-SS were higher than that of the AAC (5.0 N/mm2 and 1.64 N/mm2). While, the value of density (0.60 g/cm3) and humidity (23.59%) of AAC-SS had little less than that of the AAC (0.61 g/cm3 and 24.11%). The increasing of the tobermorite phase, which was added by the sugar sediment, had affected to the improvement of the mechanical properties. The specimens of both AAC and AAC-SS were claimed in quality class of 4, which based on the Thai Industrial Standard 1505-1998.

scholarly journals Autoclaved materials with chalcedonite addition

2018 ◽  
Vol 174 ◽  
pp. 02011 ◽  
Author(s):  
Ryszard Dachowski ◽  
Paulina Kostrzewa ◽  
Sylwia Brelak
Keyword(s):  
Compressive Strength ◽  
Pore Structure ◽  
Bulk Density ◽  
Building Material ◽  
Hydrothermal Conditions ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Ecological Building

Silicate products along with autoclaved aerated concrete are a healthy and ecological building material. Silicates and AAC are the effect of the reaction of the components from which they are formed under hydrothermal conditions. This process is called autoclaving from the name of the devices in which it runs. The tests have shown the effect of the tested additives on the particular properties of autoclaved lime-sand products and lime-sand-cement products. The addition of chalcedonite powder increased both the bulk density and compressive strength of lime-sand products and lime-sand-cement products. Composition modifications contributed to changing the microstructure of the products. In the samples with the addition of chalcedonite powder, fuller tobermorite crystals developed in comparison with the traditional sample. Additives contributed to changes in pore structure and size.

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