At what interval should control joints be placed in a reinforced concrete slab if the joint width due to shrinkage cannot exceed 0.04 in?

Note that as the slab sections shrink, the joints between the slab sections will open, and the interval between the control joints defines the length of the sections of slab.

Table 5.2 Approximate p-Values of Selected Building Materials Material p-value (R-value of 1 in. thick material) ft2.h.F Btu .in. Win. Metals Steel 0.0032 Copper ...... 0.00032 Aluminum 0.0032 Ceramic Materials Clay brick ........ 0.20 Concrete (normal weight) 0.15 Concrete (structural lightweight) .0.25-0.35 (depends on density) Concrete masonry Depends on type of concrete Limestone 0.15 Sandstone. 0.18 Glass sheet 0.14 Multiply the values given here by Gypsum wallboard, gypsum sheathing 0.60 0.176 to obtain corresponding value Portland cement plaster (stucco) .0.30 in SI system of units for 1-in.-thick Wood-Based Materials material. The unit for that value is: Solid lumber (12% moisture content). 1.2 m2.K Plywood; OSB.. 0.14 Fiberboard 2.4 Wood charcoal 2.2 Insulating Materials Silica aerogel blanket. 10.0 In plastic foam insulations (ISO, Polyisocyanurate (ISO) board-aged value .........6.0 PUR, and XPS), hydro-chloro-fluoro- Polyurethane foam (PUR)-aged value 5.5 carbon (HCFC) gas is currently Extruded polystyrene (XPS) board - aged value 5.0 used as blowing agent, which has an Expanded polystyrene (EPS) board 4.0 adverse effect on the environment. Perlite board (low-slope roof insulation) 2.8 Hydro-fluoro-olefin (HFO) gas is Insulating concrete (low-slope roof insulation) .. 1.2-1.7 gradually replacing HCFC. Fiberglass (batt; blanket; loose-fill) 3.5 Gases, Vacuum, and Water Air* 5.6 Air (air spaces in building assemblies) (See Table 5.3) Argon* 8.9 Krypton* 15.0 Hydro-chloro-fluoro-carbon (HCFC) gas 15.0 Vacuum** 40.0-50.0 Vacuum insulated panel 30.0-35.0 Water 0.24 * The p-values for gases represent heat conduction by molecular collisions and vary considerably depending on the physical dimension of spaces within which they are held. Table 5.2 Approximate p-Values of Selected Building Materials Material p-value (R-value of 1 in. thick material) ft2.h.F Btu .in. Win. Metals Steel 0.0032 Copper ...... 0.00032 Aluminum 0.0032 Ceramic Materials Clay brick ........ 0.20 Concrete (normal weight) 0.15 Concrete (structural lightweight) .0.25-0.35 (depends on density) Concrete masonry Depends on type of concrete Limestone 0.15 Sandstone. 0.18 Glass sheet 0.14 Multiply the values given here by Gypsum wallboard, gypsum sheathing 0.60 0.176 to obtain corresponding value Portland cement plaster (stucco) .0.30 in SI system of units for 1-in.-thick Wood-Based Materials material. The unit for that value is: Solid lumber (12% moisture content). 1.2 m2.K Plywood; OSB.. 0.14 Fiberboard 2.4 Wood charcoal 2.2 Insulating Materials Silica aerogel blanket. 10.0 In plastic foam insulations (ISO, Polyisocyanurate (ISO) board-aged value .........6.0 PUR, and XPS), hydro-chloro-fluoro- Polyurethane foam (PUR)-aged value 5.5 carbon (HCFC) gas is currently Extruded polystyrene (XPS) board - aged value 5.0 used as blowing agent, which has an Expanded polystyrene (EPS) board 4.0 adverse effect on the environment. Perlite board (low-slope roof insulation) 2.8 Hydro-fluoro-olefin (HFO) gas is Insulating concrete (low-slope roof insulation) .. 1.2-1.7 gradually replacing HCFC. Fiberglass (batt; blanket; loose-fill) 3.5 Gases, Vacuum, and Water Air* 5.6 Air (air spaces in building assemblies) (See Table 5.3) Argon* 8.9 Krypton* 15.0 Hydro-chloro-fluoro-carbon (HCFC) gas 15.0 Vacuum** 40.0-50.0 Vacuum insulated panel 30.0-35.0 Water 0.24 * The p-values for gases represent heat conduction by molecular collisions and vary considerably depending on the physical dimension of spaces within which they are held