Vivunja-maji ni vifaa vizito vya ujenzi vinavyotumiwa kubomoa miundo na kuvunja miamba kuwa saizi ndogo.Vivunja-hydraulic pia hujulikana kama nyundo za majimaji, rammers, vigogo au kondoo waume.Kivunja majimaji kinaweza kushikamana na mchimbaji, backhoe, skid steers, mini-excavators,...
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