ACI 330-21 Commercial Concrete Parking Lots and Site Paving Design and Construction—Guide

ACI 330-21 Commercial Concrete Parking Lots and Site Paving Design and Construction—Guide. Determining and specifying practical thickness tolerances for pavements is important. Reduction of the pavement thickness beyond tolerance recommendations can unaccept- ably increase pavement stresses, reduce pavement structural capacity, and reduce pavement life. Although construction smoothness tolerances are not critical for parking areas for low-speed trafc, smoothness is important where concrete surfaces are expected to drain well and carry water long distances across pavements with minimal slope. Aesthetic considerations of surface texture and crack control in parking lots can be important because of close scrutiny from pedestrians and the owner’s desire to project a quality image. In large parking lots, it is important to direct trafc into designated driving lanes and deter heavy vehicles from crossing thin pavements. The future expansion of a parking lot and the facility it serves should also be consid- ered during initial design so that light-vehicle pavements are not required to accommodate future heavy loads. Indus- tries and shopping centers served by public transportation, and schools served by buses are examples where expansion can transform auto parking areas into more robust truck or bus driveways. 2.2—Defnitions Please refer to the latest version of ACI Concrete Termi- nology for a comprehensive list of defnitions. Defnitions provided herein complement that resource. articulated bus—a public transportation vehicle composed of two or more rigid sections linked by a pivoting joint. California bearing ratio (CBR)—the load required to force a standard piston into a prepared sample of soil divided by the load required to force the standard piston into a well- graded crushed stone in accordance with ASTM D1883 and D1429, usually expressed as 100 times the result. curling—out-of-plane deformation of the corners, edges, and surface of a pavement, slab, or wall panel from its orig- inal shape caused by a normally-occurring combination of diferences in moisture content and temperature between the two surfaces of the panel; taken independently, temperature diferentials result in curling and moisture diferentials result in warping. (See also warping.) distributed steel reinforcement—welded wire fabric or bar mats placed in concrete pavements or slabs-on-ground to restrict the width of cracks that form between joints. frost-susceptible soil—subgrade or subbase material in which segregated ice will form, causing frost heave, under the required conditions of moisture supply and temperature. modulus of subgrade reaction, k—ratio of the load per unit area of soil to the corresponding settlement of the...