Item 18 - Appeal Application Nos. 2023-02 and 2023-03 for Cabrillo Town Center project

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Fire lane TurfBlock Turf block should be per manufactures specifications. For preliminary recommendations turf block should have a minimum thickness of 4 inches and a minimum 28-day compressive strength of 3,000 psi. The turf block pavement should be underlain by a minimum of 18-inches of aggregate base. The aggregate base material should conform to the specifications for Crushed Aggregate Base or Crushed Miscellaneous Base (Standard Specifications for Public Works Construction —SSPWC Section 200-2). The subgrade should achieve a minimum relative compaction of 90 percent per ASTM- D1557. The base material should be compacted to achieve a minimum relative compaction of 95 percent. Base and subgrade materials should be moisture -conditioned to a relatively uniform moisture content at or slightly over optimum. 4.5 Corrosivity to Concrete and Metal The National Association of Corrosion Engineers (MACE) defines corrosion as "a deterioration of a substance or its properties because of a reaction with its environment." From a geotechnical viewpoint, the "environment" is the prevailing foundation soils and the "substances" are the reinforced concrete foundations or various buried metallic elements such as rebar, piles, pipes, etc., which are in direct contact with or within close vicinity of the foundation soil. In general, soil environments that are detrimental to concrete have high concentrations of soluble sulfates and/or pH values of less than 5.5. ACI 318R-14 Table 19.3.2.1, provides specific guidelines for the concrete mix design when the soluble sulfate content of the soils exceeds 0.1 percent by weight or 1,000 ppm. The minimum amount of chloride ions in the soil environment that are corrosive to steel, either in the form of reinforcement protected by concrete cover, or plain steel substructures such as steel pipes or piles, is 500 ppm per California Test 532. Based on site soil testing, the onsite soils are classified as having a negligible sulfate exposure condition in accordance with ACI 318R-14 Table 19.3.2.1. As a preliminary recommendation due to results of sulfate content testing, concrete in contact with onsite soils should be designed in accordance with ACI 318R-14 Table 19.3.2.1 for the So/negligible category. It is also our opinion that onsite soils should be preliminarily considered corrosive to buried metals. The client and/or other members of the design team should consider this potential as they determine necessary. LGC is not a corrosion consultant and does not provide recommendations related to corrosion. 4.6 Nonstructural Concrete Flatwork Concrete Flatwork Concrete flatwork (such as walkways, patios, entryways, etc.) have a high potential for cracking due to changes in soil volume related to soil -moisture fluctuations because these slabs are typically much thinner than foundation slabs and are not reinforced with the same dynamic as foundation elements. To reduce the potential for excessive cracking and lifting, concrete should be designed in accordance with the minimum guidelines outlined below in Table 6. These guidelines will reduce the potential for irregular cracking and promote cracking along construction joints, but will not eliminate all cracking or lifting. Thickening the concrete and/or adding additional reinforcement will further reduce cosmetic distress. Project i y ouncil 18 — 839 1 3 , 2021