【正文】 風(fēng)荷載 在少于 16 到 18 層樓房中 通常不控制 構(gòu)件的大小 ，但對(duì)于高層建筑 ， 風(fēng)荷載 在結(jié)構(gòu)中 成為 重要的控制因素和引起強(qiáng)大作用力的因素 。當(dāng)跨度 較 長(zhǎng) 時(shí)，恒載的 準(zhǔn)確估計(jì)是特別重要的， 因?yàn)楫?dāng)跨度 超過(guò)七十五英尺（ 米） 時(shí) ， 恒載是設(shè)計(jì)荷載的一個(gè)重要組成部分 。 恒載值的大小直到構(gòu)件尺寸確定后才能清楚的知道 。因此，一名工程師非常謹(jǐn)慎 地 預(yù)期結(jié)構(gòu)在其一 生中 所有可能 經(jīng)受 的荷 載 ，這是非常重要的。 The American Concrete Institute ( ACI ) Building Code covering the design of reinforced concrete buildings. It contains provisions covering all aspects of reinforced concrete manufacture, design, and construction. It includes specifications on quality of materials, details on mixing and placing concrete, design assumptions for the analysis of continuous structures, and equations for proportioning members for design forces. 美國(guó)混凝土學(xué)會(huì)（ ACI ）的建筑 規(guī)范包括 鋼筋混凝土建筑物 的 設(shè)計(jì)。 The second type of code, called a building code, is established to cover construction in a given region, often a city or a state. The objective of a building code is also to protect the public by accounting for the influence of the local environmental conditions on construction. For example, local authorities may specify additional provisions to account for such regional conditions as earthquake, heavy snow, or tornados. National structural codes genrally are incorporated into local building codes. 第二種類型的 規(guī)范 ，所謂的建筑 條例 ，涵蓋 了 建設(shè)在某一地區(qū)，往往是一個(gè)城市或 一個(gè)國(guó)家 的建筑 。 A code is a set technical specifications and standards that control important details of design and construction. The purpose of codes it produce structures so that the public will be protected from poor of inadequate and construction. 規(guī)范 ，是一套技術(shù)規(guī)格和控制設(shè)計(jì)與施工重要細(xì)節(jié)的標(biāo)準(zhǔn)。鋼筋 與 混凝土 相結(jié)合 ， 可以減少其主要 的 兩個(gè)固有弱點(diǎn) 的 負(fù)面影響，其易開(kāi)裂 性 和其脆性。 Concrete, a stone like material, is made by mixing cement, water, fine aggregate ( often sand ), coarse aggregate, and frequently other additives ( that modify properties ) into a workable mixture. In its unhardened or plastic state, concrete can be placed in forms to produce a large variety of structural elements. Although the hardened concrete by itself, ., without any reinforcement, is strong in pression, it lacks tensile strength and therefore cracks easily. Because unreinforced concrete is brittle, it cannot undergo large deformations under load and fails suddenlywithout warning. The addition fo steel reinforcement to the concrete reduces the negative effects of its two principal inherent weaknesses, its susceptibility to cracking and its brittleness. When the reinforcement is strongly bonded to the concrete, a strong, stiff, and ductile construction material is produced. This material, called reinforced concrete, is used extensively to construct foundations, structural frames, storage takes, shell roofs, highways, walls, dams, canals, and innumerable other structures and building products. Two other characteristics of concrete that are present even when concrete is reinforced are shrinkage and creep, but the negative effects of these properties can be mitigated by careful design. 混凝土 石狀 的物質(zhì)，是由攪拌水泥，水，細(xì)骨料（通常砂），粗骨料，并經(jīng)常 添加 其他 外 加劑（即 改善特性 ） 而 成為 的 一 種和易性好的 混合物。一旦 這些 個(gè)別要素 的作用被 理解，設(shè)計(jì)師將有 能力 分析和設(shè)計(jì)這些元素 組成 的各種各樣 的 復(fù)雜結(jié)構(gòu)，例如地基，建筑物和橋梁。此外， 變形 隨著時(shí)間的推移將趨于增加，由于混凝土 在 持續(xù)的負(fù)荷 下的徐變 ，可能會(huì)增加一倍。因此，大跨度結(jié)構(gòu)，往往 建成鋼結(jié)構(gòu) 。上述每個(gè)步驟，涉及勞動(dòng) 力 和 /或材料， 在其他結(jié)構(gòu)形式中，這是沒(méi)有必要的 。在水支擋結(jié)構(gòu) 這種情況下 ， 需要 特別的 措施 和 /或 預(yù)應(yīng)力，以 防止泄漏。在結(jié)構(gòu)用途 時(shí) ，用鋼筋 承受拉力 ，并限制裂縫寬度在允許的范圍內(nèi)來(lái)克服 。因此，鋼筋混凝土在偏遠(yuǎn)地區(qū)經(jīng)常使用。如果致密 ， 尤其如此，加氣混凝土已經(jīng)被用于暴露于大氣中 的 表面，如果在設(shè)計(jì) 中 已經(jīng)采取謹(jǐn)慎措施，以提供足夠的排水和遠(yuǎn)離的結(jié)構(gòu)。 鋼筋混凝土建筑特殊的防火材料及其他構(gòu)造措施情況下，自身具有 13 個(gè)小時(shí)的耐火極限。同樣，鋼筋混凝土墻壁能提供有吸引力的建筑表面 ，還有 能力抵御重力 、 風(fēng)力，或地震荷載。 2. Suitability of material for architectural and structural function. A reinforced concrete system frequently allows the designer to bine the architectural and structural functions. Concrete has the advantage that it is placed in a plastic condition and is given the desired shape and texture by means of the forms and the finishing techniques. This allows such elements ad flat plates or other types of slabs to serve as loadbearing elements while providing the finished floor and / or ceiling surfaces. Similarl