Compare ! Quazite ® Precast Monolithic Polymer Concrete 17" x 30" Enclosure Dissimilar Materials 17" x 30" Enclosure Thermal Expansion Stresses The monolithic polymer concrete construction expands and contracts at the same rate ensuring that thermal expansion causes no stress on the structure. Uniform Coefficient of Thermal Expansion (CTE): 20 X 10-6 in/in/°F As temperature rises, materials expand at the rate of their CTE. When two materials with different CTE's are bonded, thermal expansion stresses result causing covers to crack. Coefficient of Thermal Expansion (CTE): Polymer Concrete: 20 x 10-6 in/in/°F Fiber reinforced polymer (FRP): 4.4 x 10-6 in/in/°F Lateral Sidewall Load 0.54" deflection at 3800 lbs.* Ensures that the box will sustain the soil surcharges created from approaching non-deliberate vehicular traffic. 0.625" deflection at 1250 lbs.* Box could fail from the soil surcharges created by approaching non-deliberate vehicular traffic. Vertical Sidewall Loading 0.35" deflection at 22,568 lbs.* Box can withstand load of non-deliberate vehicular traffic directly on top of the sidewall. 0.50" deflection at 12,423 lbs.* Weaker sidewalls could fail under non-deliberate vehicular traffic loading. Center of Cover Loading 0.18" deflection at 26,000 lbs.* Stonger resistance to breaking and cracking when loaded. 0.50" deflection at 16,000 lbs.* The cover is not as strong. Load Transfer Engineered to transfer vertical loads uniformly in a straight line to the earth without causing additional stresses to the structure. Load pressure cannot be smoothly transferred to the earth because of the angled design. At each angle, the transferred load creates stress points that may cause the box to fail. Design QUAZITE® monolithic construction assures that the cover will not crack from the stresses that occur in covers and boxes made from dissimilar materials. Box construction may cause cracking due to the stress caused by the FRP separating from the polymer concrete. Safety Factor Always design boxes with a safety factor of at least 1.5 for maximum safety precaution. Some manufacturers do not always use a safety factor of at least 1.5. Covers and boxes could fail from occasional higher than anticipated loads. Material The QUAZITE® monolithic polymer concrete box is made by mixing aggregate materials with a polymer resin. The mixture is poured into a matched surface mold lined with interwoven fiberglass cloth. The polymer resin bonds to the aggregate and fiberglass creating a stronger consistent structure for use in areas of non-deliberate vehicular traffic. The FRP base is made utilizing a spray-up or hand-lay-up production method using a one-sided open mold. Wall thicknesses depend upon a "best guess". Inconsistent sidewall thicknesses result. In a separate process, the polymer concrete ring is added. This two process method creates an overall weaker box. Water Absorption (24 hr. test) 0.09% (per ASTM D-570) Unaffected by freeze-thaw cycles due to virtually no water absorbing into the material. FRP: 0.60% (per ASTM D-570) FRP base may absorb more water creating favorable conditions for cracking during freeze-thaw cycles.