Mixture Ratio Design Optimization of Coal Gangue-Based Geopolymer Concrete Based on Modified Gravitational Search Algorithm

A green concrete, new type of coal gangue-based geopolymer concrete, was prepared. Coal gangue geopolymer concrete contains many mineral admixtures and alkaline activators; the concrete mixture ratio design has always been a complex problem. The framework of the mix design optimization by the proposed method is established in this work. The paper aims to minimize the economic cost under the premise of ensuring the strength and workability of coal gangue-based geopolymer concrete. Gravitational search algorithm (GSA) has the advantages of faster convergence speed and stronger exploitation performance compared with the traditional optimization algorithms. However, GSA tends to premature convergence and local optimum, with weak search ability. Therefore, chaotic map is introduced in the work here. Gravitational search algorithm was modified based on Chebyshev map in chaotic theory, and the modified equations were derived. The modified algorithm was verified by the calculation of typical functions. And results from traditional GSA and GSA modified by another chaotic mapping, logistic mapping, were compared and the characteristics of different GSA were analyzed and concluded. After that, the mix design of geopolymer concrete based on coal gangue with different strength grades was optimized with the modified GSA. Through analysis of the optimization results, cost variation of different strength grade coal gangue-based geopolymer concrete was revealed. Costs declined significantly; the higher the grades within a certain strength range, the more saved. Therefore, it can be inferred that the modified gravity search method provides a reliable tool for the optimization of mixture ratio of similar geopolymer concrete.

Preparation and Mixture Ratio Design of Foam Concrete with Lightweight Tailings

In this paper, the preparation technology and improved the mixture ratio design method of foam concrete with lightweight tailings have been studied. Based on the review, the following research needs have been identified: (i) to calculate the amount of lightweight tailings by the binder materials content, (ii) to calculate additional water by the water absorption of lightweight tailings saturated surface dry condition, (iii) to calculate foam stabilizer content by the weight of foaming agent. Foam should be measured by volume. By testing the wet density of foam concrete paste to accurately control the amount of foam. The foam concrete mixed with a certain amount of lightweight tailings not only can significantly reduce the content of cement, reduce cost, but also can improve the performance of foam concrete.

A Study on Ratio Design and Construction Technology of SAC Asphalt Concrete

In the process of construction, with the mixture ratio design and appropriate construction conditions of SAC asphalt concrete mixture, it can not only have dense gradation with typeIasphalt concrete which has good durability and small porosity with its skeleton dense structure, but also it can be compatible with typeIIasphalt concrete which has the ability to resist deformation and the depth of the surface structure. This paper is making an effective exploration on the construction technology and the mixing ratio design of SAC asphalt concrete with the aid of the authors construction test results of a certain highway construction.

Experimental Research on the Preparation of Heat-Resistant Concrete Using Normal Portland Cement

Based on the heat-resistant mechanism, the orthogonal experimental method and the requirements for physical-mechanical performances of heat-resistant concrete, one mixing process project was taken as the target for analysis on the mixture ratio design of heat-resistant concrete. The conventional raw materials such as normal Portland cement, common crushed aggregates, fly ash and concrete admixture were adopted to manufacture the C30 heat-resistant concrete which gets the limit heat-resistant temperature of 500°C subsequently. And the influencing factors on the strength of heat-resistant concrete were also studied in this paper. Experimental results show that the mixture ratio design of heat-resistant concrete in this paper is reasonable. The engineering application results also show it is financially viable that adopting the normal Portland cement to manufacture the heat-resistant concrete with limit heat-resistant temperature of 500°C.

Mixture Ratio Design of Inorganic Polymer Concrete and the Study of Expansive Performance

norganic polymer concrete of a new environment-friendly material has been the hot issue in engineering research so far. For this new material, the main job of the paper includes: we design mixture ratios of inorganic polymer concrete by ourselves, testing the concrete in the age periods of 3, 7, 28 d. The results indicate that this kind of material strength develops mainly in the first 3 d, the strength grows slowly in the later stage; the dry shrinkage of the configured concrete properties are measured, the curve of dry shrinkage shows that the dry shrinkage occurs mainly in the first 14 d and develops slowly in the late; And measure the expansion performance of the concrete member mixed the different categories expansive agent, the results show that the volume growth of mortar specimens to join HCSA expansion agent are obvious; Test results provide a certain basis for the inorganic polymer concrete of micro expansion.

Unascertained Average Clustering Analysis on SMA Mixture Ratio Design

Based on unascertained mathematical theory, the unascertained average clustering model (UACM) is established in the ratio design of stone matrix asphalt (SMA). Six parameters including Marshall stability, flow value, volume of air voids (VV), void in the mineral mixture (VMA), VCAmix, and asphalt saturation are selected as the index in the clustering analysis to establish UACM of design indexes including penetration, ductility, softening point, percent passing 9.5 mm sieve, percent passing 4.75 mm sieve, percent passing 0.075 mm sieve, and the asphalt-aggregate ratio respectively. The study shows that UACM has strong applicability; the results meet the engineering requirements, and can be provided a new way of SMA mixture ratio design in practical engineering.