Which is the correct slogan: "The site is cleared after work is completed and all materials are used" or "The site is cleared after work is completed and materials are used"?

It’s the latter. As for the source, which is the slogan at the construction site, it’s hard to find the source. It’s a slogan about strengthening construction site management requirements, requiring construction workers to complete the work every time ( For example, when finishing work after work), the remaining materials in the material yard (such as already mixed concrete, mortar, etc.) must be used up after completion, so that there is no excess material at the construction site. This not only requires construction workers to have good operations Professional ethics, but also requires front-line construction managers to have a high level of construction management and construction experience, and to be able to allocate materials at any time according to the workers' construction progress. This achieves the purpose of saving materials at the construction site.

Of course, if we only take it literally, both slogans will work: use up (light) all planned materials and use up all planned materials, but this slogan has two purposes. The first is economical construction, and the second is civilized construction. Cleaning also requires civilized construction requirements for workers at the construction site when they are finished. Materials cannot be saved and used up, but materials that can be saved are cleaned and stacked in order to purify the construction site