Mipiringidzo ya konkriti yatuluka ngati yofunika kwambiri pantchito yomanga, motsogozedwa ndi kulimba kwake, mtengo-mwachangu, komanso kusinthasintha. Pamene kukula kwa mizinda kukuchulukirachulukira komanso chitukuko cha zomangamanga
Palinso mitundu yambiri ya makina a njerwa pamsika, pakati pawo pali makina a njerwa otchedwa konkire block machine. Koma kodi mukudziwa zozindikiritsa makina oyika njerwa? Kodi mukudziwa zomwe zilembo za nambala ya njerwa zimayimira?
Ma midadada konkire ndi zida zomangira zofunika pantchito yomanga ndipo kupanga midadadayi kumafuna kugwiritsa ntchito makina apadera monga makina opangira simenti ndi makina osindikizira. Makinawa amagwira ntchito yofunika kwambiri