MVME2307機械設(shè)備卡件
具體指南，包括荷載組合和計算結(jié)構(gòu)耐火性的合理方法，見9.2.1.2.1.3最高使用溫度。FRP系統(tǒng)樹脂部件的物理和機械性能受溫度影響，并在接近或高于其玻璃化轉(zhuǎn)變溫度Tg的溫度下降解（Bisby等人，2005b）。商用常溫固化玻璃鋼系統(tǒng)的Tg通常在140至180°F（60至82°C）范圍內(nèi)。特定FRP系統(tǒng)的Tg可從系統(tǒng)制造商處獲得，或根據(jù)ASTM E1640通過動態(tài)力學分析（DMA）測試獲得。報告的Tg值應附有測試配置說明；樣品制備；固化條件（時間、溫度和濕度）；尺寸、加熱速率和使用頻率。由該方法定義的Tg表示在測試材料從硬脆狀態(tài)變?yōu)檐浵鹉z狀態(tài)時觀察到的儲能模量S形變化的外推起始溫度。這種轉(zhuǎn)變發(fā)生在以Tg為中心的大約54°F（30°C）的溫度范圍內(nèi)。這種狀態(tài)變化將對固化層壓板的機械和粘結(jié)性能產(chǎn)生不利影響。
對于干燥環(huán)境，通常建議FRP系統(tǒng)的預期使用溫度不超過Tg–27°F（Tg–15°C）（Xian和Karbhari 2007），其中Tg被視為構(gòu)成負載路徑的系統(tǒng)部件的最低Tg。本建議適用于高溫環(huán)境，如高溫地區(qū)或某些工業(yè)環(huán)境中的高溫環(huán)境。如果FRP將暴露在潮濕環(huán)境中，應使用濕玻璃化轉(zhuǎn)變溫度Tgw（Luo和Wong，2002）。可能需要進行測試，以確定FRP在其他環(huán)境中的臨界使用溫度。具體火災情況在9.2.1.2.1.4中有更詳細的描述。最低混凝土基底強度FRP系統(tǒng)需要粘結(jié)到完好的混凝土基底上，除非使用美國混凝土協(xié)會-版權(quán)所有?材料-www.concrete。org 6用于加固混凝土結(jié)構(gòu)的外部粘結(jié)FRP系統(tǒng)（ACI 440.2R-17）6.4中的建議。在應用FRP系統(tǒng)之前，應評估和解決現(xiàn)有鋼筋的混凝土損壞、劣化和腐蝕問題。
Specific guidelines, including load combinations and reasonable methods for calculating the fire resistance of structures, are given in 9.2.1.2.1.3 Maximum service temperature. The physical and mechanical properties of the resin components of the FRP system are affected by temperature and degrade at a temperature close to or higher than their glass transition temperature Tg (Bisby et al., 2005b). The Tg of commercial room temperature curing FRP systems is typically in the range of 140 to 180 ° F (60 to 82 ° C). Tg for a particular FRP system can be obtained from the system manufacturer or by dynamic mechanical analysis (DMA) testing in accordance with ASTM E1640. The reported Tg value shall be attached with the test configuration description; Sample preparation; Curing conditions (time, temperature and humidity); Size, heating rate and frequency of use. Tg defined by this method represents the extrapolated starting temperature of the S-shaped change in storage modulus observed when the test material changes from a hard brittle state to a soft rubber state. This transition occurs in the temperature range of about 54 ° F (30 ° C) centered on Tg. This state change will adversely affect the mechanical and bonding properties of cured laminates.
For dry environments, it is generally recommended that the expected service temperature of the FRP system does not exceed Tg – 27 ° F (Tg – 15 ° C) (Xian and Karbhari 2007), where Tg is considered the lowest Tg of the system components that make up the load path. This Recommendation is applicable to high temperature environments, such as high temperature areas or high temperature environments in some industrial environments. If the FRP is to be exposed to moisture, the wet glass transition temperature Tgw should be used (Luo and Wong, 2002). Testing may be required to determine the critical service temperature of FRP in other environments. Specific fire conditions are described in more detail in 9.2.1.2.1.4. The minimum concrete base strength FRP system needs to be bonded to a sound concrete base unless the American Concrete Institute - All rights reserved ? Materials - www concrete。 Org 6 External bonded FRP systems for strengthening concrete structures (ACI 440.2R-17). Before applying the FRP system, the concrete damage, deterioration and corrosion of existing reinforcement should be evaluated and addressed.
