Mechanical performance of aerated concrete and its bonding performance with glass fiber grille


 This paper studied the mechanical performance of aerated concrete and its bonding performance with glass fiber grille, and explores the influence of aluminum powder and aluminum powder on mechanical performance and bonding performance. The results showed that the compressive strength of aerated concrete decreased with the increase of aluminum powder content, while it first increased and then decreased with the increase of ferrosilicon alloy powder content. The failure modes of specimens were fiber fracture failure, and the fibers were not pulled out from the aerated concrete. It can provide a theoretical basis for the application of aerated concrete and glass fiber in engineering.


Introduction
At present, the prefabricated building structure system has been vigorously promoted. As vertical non-load-bearing component, internal and external partition wall panels are widely used in prefabricated building structures. Aerated concrete wall panels have light weight, good thermal insulation performance, strong seismic performance, good processing performance, inevitable high temperature resistance, good sound insulation performance, and strong adaptability are widely used. Alexanderson et al. [1], Petrov et al. [2] and Prim et al. [3] investigated the micro-structure of aerated concrete and found that the pore structure of aerated concrete was mainly divided into two levels: micro-pore structure and macro-pore structure, and analyzed the formation of pore structure. Wang et al. [4], Robler et al. [5] and Ho et al. [6] investigated the in uencing factors of the compressive strength of aerated concrete. Varela et al. [7] analyzed autoclaved aerated concrete block shear wall through quasistatic test, and developed relevant applications to optimize the structural design of autoclaved aerated concrete. Tomá [8] studied the shrinkage and damage phenomena of aerated concrete through experiments and carried out numerical simulation analysis on this basis. The research showed that the experimental phenomena of numerical simulation analysis were basically consistent with the experimental values. Yu [9] investigated the mechanical properties, failure phenomena and failure principle of aerated concrete block wall by quasi-static test. Jin [10] studied the bearing capacity of connection joints of aerated concrete wallboard under di erent factors through experiments. Leng [11] studied the bending performance of autoclaved aerated concrete slab under load through experiments, and deduced the calculation formula of ultimate bending moment according to the failure mode of slab and test data. Wu [12] studied conducted nonlinear analysis on autoclaved aerated concrete block wall using ABAQUS nite element simulation software. Zeng et al. [13] analyzed the stress-strain curve of autoclaved aerated concrete block under uniaxial compression through experimental research and theoretical analysis. Li [14] carried out experimental and theoretical studies on several connection joints of autoclaved aerated concrete wallboard, and analyzed the failure mode and the bearing capacity. Zhang et al. [15] studied the variation of ultimate bearing capacity of autoclaved aerated concrete slabs. Li [16] studied enhancing carbonation and chloride resistance of autoclaved concrete by incorporating Nano-CaCo .
The tensile properties of wall panels are mostly improved by setting steel bars in aerated concrete. However, as a traditional ductile material, steel bars have disadvantages such as self-weight and poor corrosion resistance. If a ber-forming material can be used to replace traditional steel bars, it can not only reduce the weight of the wall panel, but also improve its durability. High-strength glass ber is a good choice. Furthermore, good bonding performance between glass ber grille and aerated concrete is the premise of their joint work [17]. It is necessary to study the bonding performance of glass ber grille and aerated concrete. However, there is few studies focused on the bonding performance of aerated concrete and glass ber grille.
The purpose of this paper is to investigate the mechanical performance of aerated concrete and its bonding performance with glass ber grill, obtain the in uence of aluminum powder and ferrosilicon alloy powder on cubic compressive strength on cubic compressive strength of aerated concrete, and obtain the bonding force between aerated concrete and glass ber grill. The graphical abstract is shown in Figure 1.

Experiment . Materials and mix proportions
In this study, the cement type used for the concrete mixtures was P.O 42.5 Portland cement, the cement properties are listed in Table 1. Desulphurized gypsum was homogenized and milled by ball mill before use. The chemical composition of desulfurized gypsum is listed in Table  2. Lime meets the requirements of JC/T621-2009 [18]. The chemical composition of lime are shown in Table 3. The chemical composition of y ash is shown in the Table 4. The active aluminum content of aluminum paste is 83%, and the solid content is 74%. The water to material ratio of mix proportions of aerated concrete is 0.52, and the basis mix proportions are listed in Table 5. The glass ber properties are listed in Table 6.

. Specimens
The specimens (150 mm×150 mm×150 mm) were used to test the cubic compressive strength of aerated concrete; The pullout specimens (150 mm×150 mm×150 mm) were used to test the bonding properties of aerated concrete and di erent glass ber, and the details are listed in Figure 2.

. Loading test
The cubic specimens and pullout specimens were tested in the electro-hydraulic servo machine, and the applied load was collected by the computer. Pullout test setup is shown in Figure 3.

. Cubic compressive strength
The gas generating agent will generate a large number of bubbles inside the concrete, thereby reducing the dry den- sity and thermal conductivity of the specimen. However, it will also reduce the compressive strength of aerated concrete, so an appropriate amount of gas generating agent has an important e ect on aerated concrete. Aluminum powder and ferrosilicon alloy powder are currently commonly used gas generating agents.

. . Influence of aluminum powder on cubic compressive strength
The change curve of the compressive strength of aerated concrete with the amount of aluminum powder is shown in the Figure 4. It can be seen that the compressive strength of aerated concrete decreased with the increase of aluminum powder content, this is consistent with Zhang [19]. The reason is that as the amount of aluminum powder increases, the amount of gas generated in the paste is greater, and more pores will be generated inside the paste, which reduces the hydration products per unit volume, and the internal skeleton structure of the concrete becomes weaker, which reduce the compressive strength of aerated concrete [19]. In addition, when the aluminum powder content was less than 0.08%, the concrete strength of aerated concrete decreased slowly; when the aluminum powder content was greater than 0.08%, the concrete strength of aerated concrete decreased rapidly. Therefore, the aluminum powder content should not be greater than 0.08%.

. . Ferrosilicon alloy powder on cubic compressive strength
The change curve of the compressive strength of aerated concrete with the amount of ferrosilicon alloy powder is shown in the Figure 5. It can be seen that the compressive strength of aerated concrete rst increased and then decreased with the increase of ferrosilicon alloy powder content. When the ferrosilicon alloy powder content is 30%, the strength of aerated concrete is the highest.

. Bonding performance of aerated concrete and glass ber
The failure modes of specimens were ber fracture failure, and the bers were not pulled out from the aerated concrete.
The change curve of the bonding strength of aerated concrete specimens with the amount of aluminum powder is shown in the Figure 6. The change curve of the bonding strength of aerated concrete specimens with the amount of ferrosilicon alloy powder is shown in the Figure 7.  It can be seen that the aluminum powder and ferrosilicon alloy powder did not a ect the bonding strength of aerated concrete specimens. The reason is that the glass ber was broken before the maximum bond strength was reached. This means that there is good bonding performance between the glass ber and the aerated concrete. In addition, with the continuous development of building materials, scholars hope to apply more technologies to building materials: Liu [20] studied the addition of graphene oxide to improve the ultra-early strength of sulphoaluminate cement-based materials. Su [21,22] studied the possibility of using recycled concrete in engineering.

Conclusions
(1) The compressive strength of aerated concrete decreased with the increase of aluminum powder content.
(2) The compressive strength of aerated concrete rst increased and then decreased with the increase of ferrosilicon alloy powder content.
(3) The failure modes of specimens were ber fracture failure, and the bers were not pulled out from the aerated concrete. There is good bonding performance between the glass ber grille and the aerated concrete.

Funding information:
The authors state no funding involved.
Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.

Con ict of interest:
The authors state no con ict of interest.