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 ntawm kev ua haujlwm zoo thiab ntau yam thaiv ua tshuab. Th
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