In a recent LA Times opinion piece to promote his new book on the history of sand, Vince Beiser, an award-winning journalist, discussed concrete and warned that ‘we’re running out of one of concrete’s essential ingredients: sand’.
‘Our planet contains enormous amounts of sand, of course, but the usable type — found mostly in riverbeds, floodplains and beaches — is a finite resource like any other,’ Beiser opined. ‘Humans consume nearly 50 billion [tons] of sand and gravel every year, enough to blanket the entire state of California. Most of that is used to make concrete.’
Michael W Johnson, the president and CEO of the US National Stone, Sand and Gravel Association, has challenged the author’s contention that the US has a shortage of sand.
‘The author alleges that our country is running out of sand, which is false,’ Johnson said. He admitted however, that there were ‘incredibly long delays for new quarries to get approval to produce the sand’.
‘Most aggregates, like sand and crushed stone, are used with 50 miles of where they were produced because rocks are heavy,’ Johnson said.
‘Our infrastructure needs, and the lack of federal support, are worrisome, not the availability of sand.’
Importance of concrete
Kathleen Carr-Smith, executive vice president of communications and concrete promotion for the National Ready Mixed Concrete Association weighed in, saying: ‘We were disappointed with the inaccuracies in Vince Beiser’s LA Times article regarding concrete’s place in modern construction.
‘While infrastructure upgrades are always welcome, the assertion that a non-combustible construction material be replaced leaves us vulnerable to development with cheaper materials that put lives in danger,’ Carr-Smith added.
"The author links concrete to global carbon emissions, but only tells half the story by omitting that the sustainable and insulating nature of concrete contribute the lower lifetime energy usage and costs to heat and cool these structures, not [to] mention the implied alternative of clear-cutting for building materials threatens the ability of forests to remove carbon from the air," Carr-Smith said.
William Larson, the vice-president of marketing for CalPortland, based in Glendora, California, also refuted Beiser’s argument that concrete soaked up the sun’s heat, and contributed to countless miles of warmed-up streets and sidewalks across cities, creating a phenomenon known as urban heat islands.
Larson said societal development required solutions that lasted for generations, with less maintenance and replacement materials/activity and reduced additional environmental costs, which, he added, were consistently provided by concrete.
‘By reducing the need to rebuild, maintain and reclaim, concrete can provide protection beyond current building codes and provide the resilience for structures to perform beyond design demand and recover quicker after climatic or physical calamity,’ Larson said.
‘Research indicates that rigid concrete pavements dramatically reduce fuel consumption which in turn reduces [greenhouse gas (GHG)] emissions,’ he said. ‘Contrary to the author’s claim, [the] urban heat island is mitigated, further reducing GHG production.’
Beiser’s book The World in a Grain: The Story of Sand and How It Transformed Civilization is due to be released on 7 August.
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