More cement and pebbles. The pillars will be filled with very strong concrete. June 19, 2018February 26, 2022 Bethany Construction Bags of stronger cement are purchased for the school building pillars. I see now what Emmanuel talks about. These expensive “pebbles” are hard pieces of rock unlike the smaller less expensive “pebbles” that are various sizes of volcanic rock, which are much more plentiful. One truck load of the large pebbles cost 1,000,000 tsh, or about $500 usd. These volcanic smaller pebbles are only 250,000 tsh per truck or about $125 per truck. https://www.hearttocaretanzania.org/wp-content/uploads/sites/7/2018/06/VID-20180619-WA0003.mp4