scholarly journals The Physical and Mechanical Properties of Autoclaved Aerated Concrete (AAC) with Recycled AAC as a Partial Replacement for Sand

Buildings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 60
Author(s):  
Abdul Rahman Rafiza ◽  
Ahmad Fazlizan ◽  
Atthakorn Thongtha ◽  
Nilofar Asim ◽  
Md Saleh Noorashikin

The application of AAC has increased considerably in Malaysia since the 1990s. The usage of AAC has some advantages, but it also has negative environmental impacts since rejected concrete will become landfill. This study aimed to use AAC waste powder as a material that would partially replace the sand content to produce a new form of Autoclaved Aerated Concrete (AAC). The physical and mechanical properties of the newly developed AAC were investigated. This paper presents improved mechanical and physical properties of the new form of recycled AAC concrete. Besides these improvements, using recycled AAC could lower production costs. Furthermore, the usage of this recycled waste powder is both economically and environmentally advantageous. This study found that when recycled AAC was substituted for sand, AAC with a fine recycled powder content of 30% had a compressive strength that was around 16% higher than conventional AAC and between 29% and 156% higher than any value attained utilizing an industrial waste product. This study also confirmed that the greater strength could be identical to a higher tobermorite phase and that the recycled AAC surface showed a finer crystalline morphology.

Author(s):  
Роман Шорстов ◽  
Roman Shorstov

The article discusses the possibility of regulation by changing the amount of aluminum paste, the temperature of the mixing water and the sides of mold for the expansion of molding sand of autoclaved aerated concrete. Also, the achievement of a given maximum temperature of the array, which determines the nature of the pore structure and physico-mechanical properties of products. Mathematical models for optimizing the physicomechanical properties of autoclaved aerated concrete by regulating technological and prescription parameters are obtained using the method of mathematical planning of an experiment. It is established, optimal parameters are the mixing water temperature of 40 ... 45 ° C, the amount of aluminum paste - 0.6% of the binder mass, the temperature of the sides of the form 85 ... 90 ° C, which creates favorable conditions for the expansion of the gas-concrete mixture and the combination of pore formation and set-up structural strength of the array, allowing to obtain an optimal porous structure with smaller and uniform porosity with a sufficiently low density and high strength


2021 ◽  
Vol 1023 ◽  
pp. 141-146
Author(s):  
Inzhu Mukangali ◽  
Chang Seon Shon ◽  
Kirill Kryzhanovskiy ◽  
Di Chuan Zhang ◽  
Jong Ryeol Kim

This paper investigates the combined effect of waste soda-lime glass sand and glass fiber on the physical and mechanical properties of none-autoclaved aerated concrete (NAAC). The use of both soda-lime glass sand and glass fiber can provide silica-rich materials in the aerated concrete and can enable the elimination of an autoclaved curing by enhancing the physical and mechanical properties in aerated concrete. In this study, a total of six mixture proportions were designed to evaluate these properties in NAAC. The mixture parameters included the partial substitutions of normal sand with soda-lime glass sand (0%, 15%, and 30%) and glass fiber (1%, 2%, and 3%). A series of tests were conducted to determine density, absorption, porosity, and both compressive and flexural strengths of the NAAC. Test results present that the increase of glass sand content leads to the increasing of both compressive and flexural strengths. Moreover, the combination of the use of glass sand with glass fiber also increases the strength up to 2 times (the mixture of 30% glass sand and 3% glass fiber). Furthermore, test results indicate the relatively good relationship between the density, porosity, and of NAAC with good accuracy.


2016 ◽  
Vol 870 ◽  
pp. 163-168 ◽  
Author(s):  
N.A. Mashkin ◽  
E.A. Bartenjeva

Recently, there has been an increasing interest to the production of the non-autoclaved aerated concrete. It has a number of advantages in comparison with other materials: low power consumption of manufacturing, high fire resistance, environmental safety, bio persistence, as well as excellent insulation properties. However, its production involves a number of problems: insufficient ultimate strength, high shrinkage, high susceptibility to the parameters of technology, and the quality of raw materials. It is a well known fact that the formation of the foam concrete structure and its main running abilities are affected not only by the mortar part, but also by the chemical nature of the foaming additive, its basic physical and chemical characteristics, as well as by the parameters of foam, produced on its basis.The paper contains an assessment of availability of the technical foam production for manufacturing of the heat-insulated constructional foam at a high-speed cavitation plant involving use of fly ash from the Central heating and power plant. We used the protein and synthetic foaming agents for the work. The authors investigated the influence of process-dependent parameters of a laboratory plant on the technical foam density and foam stability coefficient in the cement paste. The physical and mechanical properties of the non-autoclaved aerated concrete produced with investigated foams are defined. The non-autoclaved aerated concrete samples with physical and mechanical properties allowing its use in production are produced.


2017 ◽  
Vol 866 ◽  
pp. 199-203
Author(s):  
Chidchanok Chainej ◽  
Suparut Narksitipan ◽  
Nittaya Jaitanong

The aims of this research were study the microstructures and mechanical properties for partial replacement of cement with Fly ash (FA) and kaolin waste (KW). Ordinary Portland cement were partially replaced with FA and KW in the range of 25-35% and 10-25% by weight of cement powder. The kaolin waste was ground for 180 minutes before using. The specimen was packing into an iron mold which sample size of 5×5×5 cm3. Then, the specimens were kept at room temperature for 24 hours and were moist cured in the incubation lime water bath at age of 3 days. After that the specimens were dry cured with plastic wrap at age of 3, 7, 14 and 28 days. After that the compounds were examined by x-ray diffraction patterns (XRD) and the microstructures were examined by scanning electron microscopy (SEM). The compressive strength was then investigated.


2018 ◽  
Vol 760 ◽  
pp. 204-209 ◽  
Author(s):  
Magdaléna Šefflová

This study deals with determination of the properties of the fine recycled aggregate (FRA) concrete with partial replacement of natural sand in concrete mixtures. The FRA was obtained from concrete waste and crushed on fraction 0 – 4 mm by laboratory jaw crusher. The geometrical and physical properties of natural sand and the FRA were tested. The main goal of this study is evaluation of the basic physical and mechanical properties of the concrete with partial natural sand replacement by the FRA such as workability, water absorption capacity, compressive strength and flexural strength. A total four concrete mixtures were prepared. The first concrete mixture was prepared only with natural sand, did not include the FRA. In other concrete mixtures, natural sand was replaced by the FRA in various replacement ratios (40 %, 50 %, and 60 %). All concrete mixtures were designated with the same parameters for clear comparison. The workability of fresh concrete mixtures and physical and mechanical properties of hardened concrete were tested.


2014 ◽  
Vol 899 ◽  
pp. 409-414 ◽  
Author(s):  
Alena Struhárová ◽  
Stanislav Unčík ◽  
Svetozár Balkovic ◽  
Mária Hlavinková

Fluidized fly ash has different physical and chemical properties compared to fly ash emerging from classic combustion. It contains amorphous phases resulting from a dehydration of clay minerals as well as unreacted sorbent of CaCO3, free CaO and anhydrite (CaSO4). Work targets the possibilities of production of an autoclaved aerated concrete (AAC) from fluidized fly ash, and its influence on particular physical-mechanical properties of autoclaved aerated concrete.


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