Cov pob zeb ua pob zeb yog cov khoom siv tseem ceeb hauv kev tsim kho kev lag luam thiab kev tsim cov blocks no yuav tsum tau siv cov tshuab tshwj xeeb xws li cov cement thaiv ua tshuab thiab thaiv cov tshuab xovxwm. Cov tshuab no ua lub luag haujlwm tseem ceeb hauv
Qhob thaiv tshuab, tseem hu ua pob zeb ua tshuab, yog cov cuab yeej tseem ceeb hauv kev tsim kho kev lag luam. Lawv tau tsim los tsim cov pob zeb ua tau zoo thiab tsis tu ncua. Cov tshuab no tau hloov zuj zus mus rau lub sijhawm, kev sib koom ua ke siab heev t
Cov pob zeb ua si ua lub luag haujlwm tseem ceeb hauv kev tsim kho kev lag luam, ua haujlwm tseem ceeb hauv kev tsim vaj tsev, phab ntsa, thiab pavements. Raws li qhov kev thov rau cov pob zeb ua vaj tse nce, yog li qhov xav tau rau cov tshuab ua haujlwm tau zoo thiab ntau yam. Th