They are employed by construction companies, cement and concrete contractors and manufacturers of precast concrete products, or they may be self-employed.
他们受雇于建筑公司，水泥和混凝土承包商和预制混凝土产品的制造商，或者他们可能成为自雇人士。
2
According to the special structure of precast block of inverted arch for TBM construction tunnel, the dynamic construction state is modeled by FEM with surrounding rock - structure calculating model.
针对TBM施工隧道仰拱预制块的特殊结构，采用围岩-结构模式，进行了模拟施工动态的受力影响计算分析。
3
In the construction sector, companies are using more precast concrete, even for high-rise apartment buildings.