ABB原装全新 DSDI452 PLC/DCS模块备件 库存实货
在一定程度上，截面形式或机械财产的任何变化，在进行适当的预防性维护后，不会降低整个设计使用寿命期间的结构安全性和结构适用性性能要求。注：冷凝是南部沿海冷凝问题区的一个问题（见附件a）。可能需要采取适当的预防措施，如提供蒸汽屏障或使用不透水材料，以确保金属屋顶板下侧、天花板水平或空隙处可能发生的冷凝水不会在结构的整个寿命期内对结构元件产生有害影响。另一种解决方案是提高热性能，从而不会发生明显的冷凝。4.2.1.9构件的制造和结构构件（或两者）的建造或安装应确保在整个设计使用寿命内，结构安全和结构适用性性能要求（适用于建筑类型）不会因质量变化和不一致而降低。4.2.1.10应根据附录B的要求进行测试，以证明符合表1至表3的具体要求（视情况而定）。注1：南非Agrément公司的性能标准：建筑和墙体系统——结构强度和稳定性中描述了合适的试验，例如，试验1：墙体横向弯曲试验2：水平荷载阻力/垂直跨度试验3：货架试验4：门上的水平荷载，窗户及其周围环境试验5：墙间L形连接强度试验6：墙间T形连接强度测试7：屋架与墙的锚固试验8：墙抵抗垂直荷载的能力试验9：山墙抵抗风荷载的能力。to the extent that any changes in sectional form or mechanical properties, subject to appropriate preventative maintenance being undertaken, do not reduce the structural safety and structural serviceability performance requirements throughout the design working life. NOTE Condensation is a problem in the Southern Coastal Condensation Problem Area (see annex A). Adequate preventative measures, such as the provision of vapour barriers or the use of impervious materials, might need to be taken to ensure that moisture from condensation that might occur on the underside of metal roofing sheets, at ceiling level or interstitially, does not have a deleterious effect on structural elements over the lifetime of the structure. An alternative solution is to improve the thermal performance such that no significant condensation occurs. 4.2.1.9 The manufacture of components and the construction or erection of structural elements (or both) shall be such that the structural safety and structural serviceability performance requirements, appropriate to the type of building, throughout the design working life, are not reduced by variations and inconsistencies in quality. 4.2.1.10 Testing in accordance with the requirements of annex B shall be used to demonstrate that specific requirements are complied with in relation to tables 1 to 3, as appropriate. NOTE 1 Suitable tests are described in Agrément South Africa’s Performance criteria: Building and walling systems – Structural strength and stability, for example, Test 1: Transverse flexure of walls Test 2: Horizontal load resistance/vertical spanning Test 3: Racking Test 4: Horizontal load on doors, windows and their immediate surround Test 5: Strength of L-connections between walls Test 6: Strength of T-connections between walls Test 7: Anchorage of roof trusses to walls Test 8: Ability of the walls to resist vertical loads Test 9: Ability of gable walls to resist wind loading.
