Chapter 14

Question 1

Precast vs Sitecast?

Answer 1

Precast concrete is cast off site and site cast concrete is cast on site, or there can be a combination of the two.

Question 2

Some elements that can be site casted are

Answer 2

Foundations
Slabs on Grade
Columns
Walls
Floors (elevated slabs, stairs, etc.)

Question 3

Slab on Grade?

Answer 3

A level surface on concrete that lies directly on the ground, which are used for roads, sidewalks and other uses.
• They carry little or no stress, transmission of superimposed loads only
• Thickness and reinforcing determined by capacity and consistency of soil and loads imposed
• Thicknesses from 3” to 18”, with several reinforcing options and WWF, Rebar/Steel

Question 4

How to prepare the slab on grade?

Answer 4

then the unstable soil is swept away, a ¾ diameter crushed stone layer Is put down, then a strip of wood is laid as a perimeter so it can be formed.

Question 5

What are expansion joints?

Answer 5

are used where slabs about walls and columns is placed to create a joint to allow for expansion and contraction as well as differential settling. There are a few ways to eliminate expansion joints like lowering the WC ratio (costs more, but reduces drying shrinkage) and added post-tensioning.

Question 6

One-Way solid slab

Answer 6

• Slabs are supported on two opposite sides, where the loads are carried in one direction.