Life Cycle Costs of Material Options for Sidewalks
In Cambridge, the current sidewalk plan allows for two different options for sidewalk materials: poured concrete or wire cut brick. A logical question arises: Which choice is better for the long run? The long run being a 40 year life cycle. To answer this question we must consider certain variables that come into play: -- Initial installation cost per square foot -- Compressive strength of the different materials which, in turn, determines the durability of the material when subjected to day to day wear -- Maintenance cost over time which, in turn, is a function of how well the materials hold up. Concrete has an advantage in initial installation cost at $55 per square yard versus $275 for wire cut brick (according to a sidewalk installer with Architectural Paving and Stone of Weymouth, MA who has worked in Cambridge). Wire cut brick has 4 to 5 times the compressive strength of concrete (12,000 to over 14,000 psi for brick versus only 3,000 psi for concrete). This difference shows up in durability over time in New England weather conditions. It has often been observed that concrete deteriorates not too long after installation, crumbling within 10 years commonly or experiencing up-thrust slabs from root growth or frost heaves. Wire cut brick lasts for the long run. Any displaced bricks can be readily reinstalled with modest effort. Maintenance cost is far less for wire cut brick compared with concrete. Experience shows concrete crumbles within 10 years or less so would have to be materially maintained at least four times in a 40 year period. Brick, on the other hand, is far more durable and needs minimal maintenance in a 40 year period, if sand-set, mainly resetting displaced individual bricks due to root growth or slippage in place. According to the Vice President of Sales and Marketing for Pine Hall Brick of North Carolina, the maintenance cost per square yard over 40 years is $220 for concrete but only $18.33 for wire cut brick. Which means the 40 year life cycle cost of the two materials per square yard is $275 for concrete and $293.33 for brick. Reinforcing this point is what little data we could find on maintenance costs incurred for sidewalks in Cambridge. Concrete maintenance and repair cost was over $20 million in the past 10 years versus negligible for brick. All in all, it would appear that use of concrete for sidewalks is penny wise and pound foolish. Brick would appear to be the clear choice for the long run, not to mention the fact that brick is consistent with the historical legacy of brick sidewalks that the City has had for more than 200 years. Reinforcing this point is what little data we could find on maintenance costs incurred for sidewalks in Cambridge. Concrete maintenance and repair cost was over $20 million in the past 10 years versus negligible for brick. All in all, it would appear that use of concrete for sidewalks is penny wise and pound foolish. Brick would appear to be the clear choice for the long run, not to mention the fact that brick is consistent with the historical legacy of brick sidewalks that the City has had for more than 200 years. Regards. Diane
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11/12/2022 06:33:55 am
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AuthorDiane W. Beck
VP and Board Member Archives
December 2019
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