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The aim of the current study is to investigate the carbonation behavior of cement hydrates at different environments. Hardened cement pastes are prepared using OPC and BFS and crushed into ~90μm powder. The powder samples are carbonated at 5/20% CO2 and at 60/85%RH. TGA, XRD and phenolphthalein tests are conducted before and after carbonation. The results show that CH remain uncarbonated even after CO2 uptake apparently ended and that the amount of the residual CH affects the results of phenolphthalein test. External humidity strongly affects the carbonation behavior of both CH and other hydrates. The degree of CH carbonation is greater at higher humidity, while the degree of other hydrates carbonation is greater at lower humidity. This conflicting effect can occur at surface of bulk concretes and changes in its properties (coarsening of pore structure and cracking) can be caused without apparent carbonation detected by phenol phthalein test. The effect of relative humidity on CSH carbonation should be taken into consideration when estimating long-term performance of carbonated concretes.

With regard to fire safety for exterior walls of a building, fire-resistance performance is considered, according to the current building standard law of Japan. And it was revealed that the fire safety is not specifically regulated from the viewpoint of reaction-to-fire performance, such as fire propagation caused by combustible materials or products which are installed on the exterior side of fire-resistant load-bearing walls. Actual fire issues in the world have shown that massive facade fire could occur at the exterior side of building wall even when the wall itself is fire-resistant. In previous studies of the authors, a test method of facade fire was tentatively proposed for evaluating the vertical fire propagation over an external wall within the same building. Furthermore, especially at the high-density residential areas in Japan, fire spreading would occur mostly from window to window between adjacent buildings, while walls are not burning by facade fire. But in case of combustible facades, such as insulating materials, combustible coating, or even sandwich panel are installed on the wall surface, once they are ignited, facade fire would occur and accelerate both the fire propagation in the same building and the fire spreading to the adjacent building. In this paper, results of fire tests on combustible facades are discussed from the viewpoints of both vertical fire spread along facades and fire spread between adjacent buildings assuming the densely populated residential area in Japan. The tentative criteria were determined based on the time to reach 500°C and duration time exceeding 500°C on facade surface for vertical fire spread along facade. As for intensively burned cases, at 2500 mm height from upper edge of the opening, specimens of exterior thermal insulation system with 200-mm thick expanded polystyrene (EPS), aluminum composite panel with polyethylene core and wooden facade without fire-retardant treatment continued exceeding 500°C for 3.1 min, 5.7 min, and 3.6 min, respectively, that were longer duration compared with specimens of resin painting (approximately 1 min). On the other hand, the another tentative criteria were determined for horizontal fire spread to an adjacent building based on the duration time exceeding the calibration test’s peak incident heat flux on opposite surface 2000 mm from facade surface for horizontal fire spread to an adjacent building. At 500 mm height from upper edge of the opening, specimens of exterior thermal insulation system with high-density 100-mm thick EPS and wooden facade without fire-retardant treatment continued exceeding the peak incident heat flux of calibration test for 13.1 min and 13.6 min, respectively, while one specimen of resin painting and aluminum composite panel with polyethylene core continued for shorter duration of 4.2 min and 5.8 min, respectively, even though they showed relatively high peak facade surface temperatures.

With regard to fire protection for exterior walls of a building, only fire-resistive performance is considered, according to the current building standard law of Japan. In previous authors' studies, a new test method for evaluation of fire propagation along combustible cladding was proposed using primarily test specimens of facade walls with exterior thermal insulation without vent layers. In this paper, newly made results of facade fire tests also with other specimens of combustible facades, such as sandwich panels, photovoltaic sheets, combustible coating materials, and exterior insulation with vent layer, are discussed.

Wood has been used for building facades to enhance the aesthetic design of buildings since the revision to the evaluation method associated with the amendment of the Building Standard Law of Japan in 2000. In response, wood that has been pressure-impregnated with fire retardants (fire-retardant treated wood) is often used to ensure it is safe in the event of a fire. Currently, when fire-retardant-treated wood is tested for certification of reaction to fire performance, a cone calorimeter test is conducted in Japan. This test applies radiant heat to the surface of a square specimen, 100 mm each side, immediately after it has undergone fire-retardant treatment. However, when applying fire-retardant treatment to wood, aqueous chemical injection is the standard procedure. When wood is actually used to construct a building, there is a concern about environmental forces such as wind and rain that could cause the wood to deteriorate, and concerns about performance degradation associated with aging. One of the past studies in Japan [1] conducted a cone calorimeter test after an outdoor exposure test and accelerated weathering test, compared the post-test performance with the initial performance and confirmed the amount of remaining fire retardant in the treated wood had been reduced. However, no comparison of the fireproof performance of fire-retardant wood in actual use in a building facade had been conducted in Japan. There have been already valuable researches [e.g. 2, 3] on this issue internationally, but this paper is the first step in Japan and authors hope to focus on the wooden facade construction technique and the standard facade test in Japan. © Owned by the authors, published by EDP Sciences, 2016 Language: en

With regard to fire safety for exterior walls of a building, fire-resistance performance is considered, according to the current Building Standard Law of Japan. And it was revealed that the fire safety is not specifically regulated from the viewpoint of reaction-to-fire performance, such as fire propagation caused by combustible materials or products installed on the exterior side of fire-resistant load-bearing walls. Actual fire incidents in the world have shown that massive facade fire could occur at the exterior side of building wall even when the wall itself is fire resistant. In previous studies of the authors, a test method of facade fire was proposed for evaluating the vertical fire propagation over an external wall within the same building [1,2]. Based on these studies, new domestic standard test method was established in Japan as JIS A 1310: 2015, "Test method for fire propagation over building facades" at the end of January 2015 [3]. But there was the argument that heat output of burner inside the combustion chamber was not sufficiently high in the previous study. In this paper, results of fire tests on combustible facades are discussed from the viewpoints of different strength of flame exposing facade. In this research, it was clearly found that JIS A 1310 with heat output of 900kW could be applicable for evaluating fire propagation behaviour over various types of combustible exterior facades. Language: en

With regard to the fire protection for exterior walls of building, only the fire resistance has been considered, according to the current building law of Japan. In the previous studies of the authors, a new test method for evaluation of fire propagation along combustible cladding was proposed using primarily test specimens of façade walls with exterior thermal insulation without vent layers. In this paper, newly obtained test results are discussed on other specimens of combustible façades such as wood, sandwich panel, photovoltaic sheet mounted on composite panel, combustible coating material, and exterior thermal insulation with vent layer.