It took 366 trucks carrying 3,294 cubic yards of concrete, but the foundation for Rincon Hill’s next residential tower is now in place. With the first residents moving into into the 754-unit NEMA apartment tower at 14 10th St., Crescent Heights is going full speed ahead on its next San Francisco highrise: a 400-foot tower at 45 Lansing that will add 320 units to the growing Rincon Hill neighborhood. On Saturday night San Francisco-based contractor Build Group completed an 21-hour mat pour for the tower, which is being designed by HKS. The pour started at 6 p.m. on Saturday night and didn’t wrap up until 2:30 p.m. the next day. Mat sections ranged from five to seven feet thick to 14-feet thick in the shear walls around the core of the building. Over 120 people were on-site throughout the pour including field staff, off-site support, and truck drivers. Concrete batches came from two plants, one in South San Francisco and one in Oakland. Build Group provided coffee, bagels, and workers provided free “concrete lessons” to curious neighbors to keep them informed of what was happening.