预应力筋室外存放时应当（　　）。

【解题思路】本题考查预应力钢筋的存放。选项C错误，<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>防老化</strong></span>是<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>塑料</strong></span>材质材料的存放要求。预应力钢筋和金属管道在室外存放时，时间宜不超过<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>6个月</strong></span>，<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>不得</strong><strong>直接</strong><strong>堆放在</strong><strong>地面</strong><strong>上</strong></span>，必须采取<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>垫以枕木</strong></span>并用<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>苫布覆盖</strong></span>等有效措施，<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>防止雨露</strong></span>和各种<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>腐蚀性气体</strong></span>、<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>介质</strong></span>的影响。【知识拓展】预应力钢筋和金属管道在<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>仓库内保管</strong></span>时，仓库应<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>干</strong><strong>燥</strong></span>、<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>防潮</strong></span>、<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>通风良</strong><strong>好</strong></span>、<span style="text-decoration: underline; color: rgb(224, 62, 45);"><strong>无腐蚀气体和介质</strong></span>。