Fair-faced Concrete Research Articles

Study on strength and durability of fair-faced concrete in underground station of urban rail transit

Concrete is still in the developing stage in China, only some design and construction units can master its construction technology. The side walls and middle columns of underground station of Changzhou Metro Line 2 are made of fair-faced concrete. In this paper, the material properties of the underground station are studied based on the project. In this paper, the working performance, compressive strength, impermeability, sulfate corrosion and carbonization resistance of fair-faced concrete are mainly studied by drawing up the base mix ratio. The research results have reference value for the future development of fair-faced concrete engineering.

Robustness interval of apparent air bubbles of fair-faced concrete

In this paper, a method of controlling the apparent quality of fair-faced concrete is adopted. By adjusting the rheological parameters of fair-faced concrete slurry, the robustness interval of repeatedly stable preparation of fair-faced concrete with excellent apparent quality is obtained. It has a good economy and has a good guiding significance for practical engineering. The results show that the plastic viscosity coefficient of fair-faced concrete slurry is 5.67∼9.69 Pa·s, and the yield stress is between 112.25∼195.68 Pa. The fair-faced concrete with good apparent quality can be obtained.

Discussion on the characteristics and construction technology of fair-faced concrete

Discussion on the characteristics and construction technology of fair-faced concrete

The correspondences between formwork geometry and concrete composition in the case of fair-faced concrete elements

Modern architecture is unimaginable without fair-faced concrete. However, there is no generally accepted method for design the suitable concrete composition to get the required surface quality. Thi...

Expounding the Construction Technical Measures of Fair-Faced Concrete Construction

Due to the acceleration of urbanization in China, construction technology in the construction field has also been continuously developed. The fair-faced concrete is often referred to as decorative concrete. It is a new type of concrete that has been continuously developed as people's demands for architectural decoration and it becomes more widely used in modern construction projects. In this paper, by introducing the types and composition of fair-faced concrete, a series of fair-faced concrete construction technical measures, as well as pouring and conservation measures, have been proposed in conjunction with actual construction projects, and examples have been analyzed in order to better apply the fair-faced concrete technology into modern buildings.

砂浆塑性粘度对自密实清水混凝土表观性能的影响

砂浆塑性粘度对自密实清水混凝土表观性能的影响

Mould release technologies with regard to concrete surface finish

Concrete durability is in part dependent upon the quality of the concrete cover zone. The type of mould release technology used has a direct effect on the surface finish of fair-faced concrete, and this in turn affects long-term durability. This work examined two mould release agents (MRAs), one permeable formwork liner and a type 1 polypropylene fibre concrete combined with a single MRA. Cubes were cast in film-faced plywood moulds using C40 concrete that enabled comparisons to be drawn between the MRAs. The pilot study examined a range of variables for two different reactive MRAs (FS (petroleum based) and CL (vegetable oil based)). The release agents used are commercially available as reactive-based MRAs. In addition, controlled permeability formwork (CPF) and a concrete mix with polypropylene fibre additions were used. The pilot study results showed that the CPF liner produced the least number of blowholes and, in that respect, was the best performing technology used. Consequently, the CPF provided the most likely finish that would provide long-term durability. None of the technologies employed produced a completely uniform colour throughout, but the CL MRA cubes and polypropylene fibre reinforced cubes produced the most consistent colouring. Two of the best performing mould release products (CPF and FS) were then tested using a high-resolution optical measurement system and the initial results were examined in much greater detail, taking account of surface roughness, pore volume and pore size. The CPF proved to produce a better finish than the FS release agent.

Characterization of concrete surface in relation to graffiti protection coatings

The removal of graffiti causes irreversible deterioration of fair-faced concrete. The protective products are often selected without counting the properties of concrete surface leading to its insufficient protection. Chemical and micro-structural effects of anti-graffiti products on the concrete surface were analyzed in relation to its protection efficiency against graffiti paints. Contact angles and wetting envelope graphs were examined, allowing the understanding and prediction of wetting behavior of concrete surfaces. The obtained results revealed the changes on the concrete surface produced by graffiti, graffiti protection and graffiti removal products, showing the advantage of permanent protection coating over sacrificial one.

Effects of Anti-Graffiti Protection on Concrete Durability

The heritage of fair-faced concrete, largely built in the twentieth century and nowadays recognized as heritage to be protected, is susceptible to attacks by graffiti, a form of vandalism that causes a major social and economic impact on society. Concrete is a porous material sometimes deteriorated over the years, and the interactions between the inks and the substrate and removal methods sometimes deteriorate or alter the concrete surface, especially if it is necessary to repeat the removal process. The anti-graffiti products are applied on the surface of the concrete, hindering the adhesion of paints or preventing its penetration into the pores of concrete, which in turn facilitates their removal. However, it appears that many of the existing protective products on the market may also alter the surface characteristics of the concrete irreversibly. Considering that the durability of concrete depends on the composition and characteristics of the surface, it is essential to know the effects of anti-graffiti protection systems on the durability of concrete and adopt the appropriate methodology to preserve this heritage. Thus, an experimental program was developed for analyzing changes in durability indicators and surface properties that protect concrete from deterioration (i) concrete without protection before and after application of spray paint, (ii) concrete with protection before and after application of spray paint and (iii) after paint removal were studied. Two anti-graffiti products were evaluated: a permanent and a sacrificial one. Effects of the anti-graffiti systems on the concrete durability are investigated and the tests performed include: water absorption by capillary and immersion at atmospheric pressure. The results of the water absorption tests show that the graffiti protection reduces the water absorption into the concrete and facilitates the removal of the graffiti without affecting negatively the characteristics of the surface and thus contributing to improve its durability.

Experimental Study on Basic Properties of Fair-Faced Concrete for Urban Bridge

As the high-performance concrete with remarkable characteristics of artistic presentation and ecological sense, fair-faced concrete is becoming more and more attention by the department of urban construction. As part of the research project, this paper gives the supplement study of the mix proportion and basic properties of C50 fair-faced concrete, and summarizes the experimental results of the apparent quality of C30 and C50 fair-faced concrete affected by the mold releases. Considering the parameters of water to cement ratio, cement dosage, percent of pulverized fly ash, sand ratio, water reducer and mold releases, the workability of fresh concrete and the compressive strength of hardened concrete at 7 days, 28 days and 56 days, as well as the apparent quality and surface brightness were measured, the mix proportions of C30 and C50 fair-faced concretes for construction of urban bridge were determined. Based on the measurements of surface brightness, color uniformity, resistance to water penetration, stain resistance and compressive strength of fair-faced concrete, the formwork lacker can be firstly selected as the mold release, and the mix oil (diesel: machine oil=3:7) can be the alternative selection.

Simulated Environment Test on Weather Fastness of Fair-Faced Concrete for Urban Bridge

To keep the perfect, artistic and natural characteristics of fair-faced concrete, it is necessary realizing its weather fastness. This paper introduces the simulated environment test for weather fastness of fair-faced concrete considering the environmental actions at all seasons such as washing of acid rain, sand blown by the wind, exposure to blazing sunlight, salt-fog, carbonization and freeze-thaw. Test methods for sand blown by the wind, washing of acid rain, slow freeze-thaw and exposure to blazing sunlight were invented. The mass change of concrete were measured, and the surface quality was evaluated by the glossiness, the pixel difference and the variance of pixel difference. The results showed that the mass had a little change under the comprehensive actions. The factors decreasing the surface quality in sequence from serious to slight were the washing of acid rain, the salt-fog, the freeze-thaw and the carbonization. The erosion degree increased with the increasing pH value in rainwater and the increasing density of sulfate-ion in salt-fog solution. The surface of concrete damaged by the long-term freeze-thaw and carbonization. The sand blown by the wind, and the exposure to blazing sunlight had little influence on the surface of concrete.

Experimental Research on Durability of Fair-Faced Concrete

Fair-faced concrete is a neotype constructional material. It is exposed to the natural environment directly as decorative walls in the acting process, so the request of durability of the concrete is much higher. Through comparison testing, data collection and analysis, find out the difference of durability of fair-faced concrete in different proportioning. It has positive significance to the selection of raw material and construction technology.

Construction Technology and Benefit Analysis of Fair-Faced Concrete in High-Rise Building

As a new kind of concrete construction technology, fair-faced concrete is still not mature and applied widely in China by present. But it was successfully used in China Qingdao Zhuoting plaza project. Its No.1 and No.2 dwelling houses are high-rise buildings with thirty-two stories and their external walls were constructed with fair-faced concrete. As it is the highest fair-faced concrete project in China with 99.95m in height and 370 days construction period through four seasons in a year, the project meets a lot of problems and challenges. So some innovative construction technologies were studied and used which make the project smoothly and successfully completed and get many significant economic, social and environmental benefits.

Construction Technology and Benefit Analysis of Fair-Faced Concrete in High-Rise Building

As a new kind of concrete construction technology, fair-faced concrete is still not mature and applied widely in China by present. But it was successfully used in China Qingdao Zhuoting plaza project. Its No.1 and No.2 dwelling houses are high-rise buildings with thirty-two stories and their external walls were constructed with fair-faced concrete. As it is the highest fair-faced concrete project in China with 99.95m in height and 370 days construction period through four seasons in a year, the project meets a lot of problems and challenges. So some innovative construction technologies were studied and used which make the project smoothly and successfully completed and get many significant economic, social and environmental benefits.

Key Construction Technology of Fair-Faced Concrete on China Qingdao Zhuoting Plaza Project

Construction technology of fair-faced concrete was successfully used in China Qingdao Zhuoting plaza project. Its No.1 and No.2 dwelling houses are high-rise buildings and their posts and external walls were constructed with fair-faced concrete. As it is the highest fair-faced concrete project in China with 99.95m in height , four different concrete strength grades from C35 to C50 on different floors,370 days construction period through different four seasons in a year, the project meets a lot of problems and challenges. In this article, some innovations and key construction technologies were studied and used which make the project be successfully completed.

Key Construction Technology of Fair-Faced Concrete on China Qingdao Zhuoting Plaza Project

Construction technology of fair-faced concrete was successfully used in China Qingdao Zhuoting plaza project. Its No.1 and No.2 dwelling houses are high-rise buildings and their posts and external walls were constructed with fair-faced concrete. As it is the highest fair-faced concrete project in China with 99.95m in height , four different concrete strength grades from C35 to C50 on different floors,370 days construction period through different four seasons in a year, the project meets a lot of problems and challenges. In this article, some innovations and key construction technologies were studied and used which make the project be successfully completed.

Experimental Study on Mix Proportion of Fair-Faced Concrete for Urban Bridge

As the needs of fair-faced concrete structures for the ecological environment, this paper studies the mix proportion of fair-faced concrete in C30 strength grade by experiments. 13 concretes were designed and tested considering the water to cement ratio, the cement content, the percent of pulverized fly ash, the sand ratio, the water reducer and the formwork parting agent. The workability of fresh concrete, the compressive strength of hardened concrete at 7d, 28d and 56d, and the apparent quality as well as the surface brightness of concrete were got. The results show that the surface color and brightness of concrete were influenced successively by the cement content, the water to cement ratio, the sand ratio and the percent of pulverized fly ash. The use of formwork lacker may bring concrete into better brightness, while the mix oil may be a good selection considering the cost of parting agent. The suitable mix proportions of C30 concrete for urban bridge are proposed.

Experimental Study on Mix Proportion of Fair-Faced Concrete for Urban Bridge

Experimental Study on Mix Proportion of Fair-Faced Concrete for Urban Bridge

Experimental Study on Durability of Fair-Faced Light Weight Aggregate Concrete

Fair-faced light weight aggregate (FLWA) concrete is of all good performance of both LWA and fair-faced concrete. There is a fluorocarbon coating on its surface. This paper studies on how this paint influences FLWA durability.

Development and Application of High-Performance Self-Compacting Fair-Faced Finish Concrete under Complex Conditions

With the support of the Wuhan railway station of Passenger Transport Line from Wuhan to Guangzhou which was completely furnished, the characteristic of zeolite in concrete made best of, the main factors including cementing materials, additives, admixtures and sand rates were researched through experiment and the effective testing method determined, the self-compacting fair-faced finishing concrete is achieved, and 6600m³ of the concrete is applied. The developed self-compacting concrete has good effect finish, reduce the labor intensity by the character of self-compacting, and save construction period. The level of Green construction is also upgraded.