Rethinking Durability

first_img This article is only available to GBA Prime Members Sign up for a free trial and get instant access to this article as well as GBA’s complete library of premium articles and construction details. Does durability matter? Most green building advocates seem to think that green builders should always aim to build durable structures. My own opinion differs; in fact, as I explained in a 2009 article on the topic, it’s hard to see any correlation between durability and “greenness.”I recently had an opportunity to reconsider the advantages and disadvantages of durability when my wife and I visited the Pont du Gard in Languedoc-Roussillon, France.The 2,000-year-old Pont du Gard is a remaining section of what used to be a 31-mile-long Roman aqueduct that conveyed water from a spring in Uzès to the city of Nîmes. Most of the aqueduct was buried; the buried sections of aqueduct resembled a masonry culvert lined with waterproof plaster. But Roman engineers knew that they couldn’t bury the section of the aqueduct that crossed the Gardon River. The technical solution to the river crossing was a 160-foot-tall stone bridge — the Pont du Gard — with an aqueduct on top.The Pont du Gard is built of dressed limestone blocks, assembled without mortar (see Image #2 at the bottom of the page).In ancient Roman times, the aqueduct conveyed 44 million gallons of water per day to the public baths, fountains, water spouts, and cisterns of Nîmes. (That amount of water would adequately meet the needs of 138,000 modern American homes.)Without any maintenance, the aqueduct continued to supply fresh water to Nîmes for 300 to 400 years. Unfortunately, mineral buildup gradually reduced the size of the aqueduct’s channels; eventually, in the 4th or 5th century A.D., the aqueduct ceased functioning.For centuries after water stopped flowing through the aqueduct, the Pont du Gard continued to be used as a pedestrian and equestrian bridge.The Pond du Gard has long been a pilgrimage destination for civil engineers… center_img Start Free Trial Already a member? Log inlast_img read more

Voting begins for Dantewada Assembly bypoll in Chhattisgarh

first_imgVoting for the bypoll to the Naxal-affected Dantewada Assembly constituency began on Monday morning amid tight security. The bypoll was necessitated due to the death of BJP MLA Bhima Mandavi in a Naxal attack in April. Polling began at 7 am and it will go on till 3 pm, an election official said here. A total of 1,88,263 voters, including 89,747 men and 98,876 women, are eligible to exercise their franchise in the constituency, which has 273 polling stations. A massive security blanket of around 18,000 personnel, including those from paramilitary forces, and drones have been thrown around the Dantewada Assembly segment, which is part of the insurgency-hit Bastar region, for conducting peaceful polling, a police official said. The counting of votes will be taken up on September 27. Nine candidates are in the fray for the seat, the only one in Bastar division that the Bharatiya Janata Party (BJP) managed to win in last year’s Assembly election. Both the ruling Congress and the BJP have fielded candidates who have been victims of Naxal violence, with the former pitting Devti Karma, wife of senior party leader Mahendra Karma who was killed in the Jhiram Valley attack in 2013, against the latter’s Ojaswi Mandavi, wife of slain MLA Bhima Mandavi. The other candidates are Hemant Poyam (Bahujan Samaj Party), Sujit Karma (Janata Congress Chhattisgarh (J)), Bhimsen Mandavi (Communist Party of India), Ajay Nag (Nationalist Congress Party), Ballu Ram Bhawani (Aam Aadmi Party), Yogesh Markam (Gondwana Gantantra Party) and Independent Sudru Ram Kunjam. Stakes are high for the main opposition BJP as it is fighting to retain the seat. In the 2018 Assembly polls, Devti Karma had lost to Bhima Mandavi by a thin margin of 2,172 votes in the Dantewada seat. In the 90-member state Assembly, the Congress won 68 seats last year and the BJP 15. The Janata Congress Chhattisgarh (J) and the BSP had bagged five and two seats respectively.last_img read more