Past Issues
Issue #032
November 3, 2026
Steel inside good concrete does not rust. Concrete's own alkalinity protects it, until chloride or carbonation strips that protection away and the steel begins to rust and swell. This week: the dam whose gate walls were corroding from the salt in the water.
Issue #031
October 27, 2026
A concrete repair is the easy part. Making it last is the hard part, and about half of concrete repairs fail. This week: the stilling basin ground away by its own river, and the silica-fume repair that finally held.
Issue #030
October 20, 2026
A big concrete dam is never still. It leans with the reservoir and breathes with the seasons, all reversible. Watching for the small movement that does not reverse is the whole art of dam surveillance.
Issue #029
October 13, 2026
You can inspect a dam's faces all you like. The concrete that decides whether it holds is metres deep and will never be seen. This week: how a pulse of sound reads the inside of a dam.
Issue #028
September 29, 2026
A calcite bump six millimetres high, on the floor of a Glen Canyon spillway tunnel, triggered cavitation that tore a 35-foot hole into solid sandstone in a single flood season. Not thicker concrete but air was the fix.
Issue #027
September 22, 2026
You can pour a flawless dam and still lose it to the rock underneath. Most concrete dams that fail, fail in the foundation. This week: the grout curtain, the karst that kept defeating it, and how to close one.
Issue #026
September 15, 2026
Sound concrete barely leaks. Water finds the joints, the lift lines and the cracks. One dam tried to save money by leaving its contraction joints out, then spent years and millions learning why they are not optional.
Issue #025
September 8, 2026
To a purchase order, cement is cement and fly ash is fly ash. To the concrete, they are anything but. Both swing batch to batch in the properties that decide strength, heat and durability, and the cost of that swing is paid in a margin you never see.
Issue #024
September 1, 2026
The Dam Safety Act gives every specified dam five years to complete its first comprehensive evaluation, and that window closes on 30 December 2026. Buried in Section 38 is a clause that makes concrete integrity a named line item.
Issue #023
August 25, 2026
In India the monsoon is not weather you work through. It is a boundary that reorganises the whole pour. The quiet hazard is not the rain you can see. It is the water in the aggregate, and the joint the rain forces you to leave.
Issue #022
August 18, 2026
Some dams have a disease with no cure. The concrete swells from within, jams the gates, and pushes the turbines out of line, and it will not stop. So the engineers saw slots into the dam to give the growth somewhere to go, and then they saw them again.
Issue #021
August 11, 2026
The cast cube says the concrete passed. The drilled core comes back lower, and the site starts talking about demolition. But a core is allowed to read below the grade and still pass, because it is measuring a different thing.
Issue #020
August 4, 2026
Poured as one mass, Hoover Dam would have needed a century and a quarter to cool, and cracked itself apart in the process. So its builders ran chilled water through 582 miles of pipe buried in the concrete. Thermal control is not a finishing touch. It is how a dam gets built.
Issue #019
July 28, 2026
A pumped-storage upper reservoir is a pond on high ground with almost no river feeding it, filled and emptied every day. It cannot be allowed to leak, because nothing flows in to replace what leaks out. On these dams the face is not a detail. It is the dam.
Issue #018
July 21, 2026
The white deposits growing in a dam's inspection gallery are not a curiosity. They are the lime out of the concrete, dissolved by soft water and re-precipitated where the seepage meets air. Which means the cheapest diagnostic on the site is already running out of your drains.
Issue #017
July 14, 2026
The Son La dam was built on sixty kilograms of cement per cubic metre, a fraction of ordinary concrete, because nearly three-quarters of its binder was fly ash. The mix that keeps a mass dam from cracking turns out to be the one that carries the least carbon.
Issue #016
July 7, 2026
For as long as there was a choice, river sand was the good material and crushed sand the fallback. India's rivers are running out of sand, and where builders have been forced onto crushed rock, it has turned out to be the better material anyway.
Issue #015
June 30, 2026
A calcite bump six millimetres high, under fast enough water, cut a crater 35 feet deep through a concrete spillway tunnel and into the bedrock beneath, in a single flood season. The damage was not done by anything in the water. It was done by the water.
Issue #014
June 23, 2026
At Malpasset the arch shell was sound. The rock beneath the abutment was not, and more than 420 people died for it. The most consequential concrete on a dam is the part you bury and never see again: the grout curtain in the foundation.
Issue #013
June 16, 2026
A dam under load is never silent. It reports on itself through its instruments, each one the early warning for a different way to fail. The problem on India's ageing dams is not what the instruments say. It is that many have stopped speaking.
Issue #012
June 9, 2026
A cement tanker reaches the dam site. The mill certificate passes IS 269 on every line. Three lifts later the thermocouples read hotter, and nobody touched the mix. The two numbers that explain it are not on the certificate.
Issue #011
June 2, 2026
The monsoon is breaking over the coast. The next interrupted pour will form a joint. Whether it is hot, warm, cold, or super cold is not the QC engineer's opinion. It is the product of two numbers, and Teesta Low Dam Stage-IV wrote down what each one demands.
Issue #010
May 26, 2026
A 7-day cube reads 1.25 MPa against a 17.5 MPa target. Every conventional acceptance criterion says reject. The roller-compacted concrete in the cube delivered 24.50 MPa at 365 days. The two RCC dams that taught Indian practice why early-age cube failure is sometimes the correct behaviour.
Issue #009
May 19, 2026
Spillway potholes between one and six metres deep, in each of 26 blocks of the dam long described as the world's largest masonry dam. What recent inspections at Nagarjuna Sagar are saying about ageing concrete infrastructure under the CDSE clock.
Issue #008
May 12, 2026
August 1979, Machchhu II. December 2026, every existing specified dam in India. Forty-two years from a disaster to a law. Seven months left until the deadline that law set.
Issue #007
May 5, 2026
Polavaram's 1.5-metre plastic concrete diaphragm wall, the first of its kind in India, was damaged across two monsoons because the upper cofferdam was not built up in time. The pre-monsoon staging lesson before May becomes June.
Issue #006
April 28, 2026
IS 7861 sets a 40 degree C threshold. ACI 305.1 sets a 35 degree C ceiling. Hoover Dam would have taken 125 years to cool naturally. The Watch / Intervene / Stop framework for summer placement on dam sites.
Issue #005
April 21, 2026
Willow Creek Dam leaked so badly that a full year of grouting was needed after first filling. The lesson it taught the RCC industry is still misunderstood on Indian sites today.
Issue #004
April 14, 2026
India's third RCC dam needed 210 tonnes of fly ash per day from a thermal plant 320 km away. 29 trucks. One narrow Himalayan road.
Issue #003
April 7, 2026
AAR worked silently inside Rihand Dam for 25 years before snapping 9 of 10 rebars in a single column. How the most dangerous deterioration mechanism hides in plain sight.
Issue #002
March 31, 2026
When your 28-day cylinder breaks low, is the concrete deficient or is the test wrong? The NYC lab fraud scandal that faked results on 120 projects.
Issue #001
March 24, 2026
How a monsoon flood forced India's first RCC dam switch at Ghatghar, costing Rs 500 million and 13 months. Plus: 80% of India's dams are over 25 years old.
Concrete Pulse is our weekly newsletter on concrete technology for dam and infrastructure engineers. New issues every Tuesday at 10:00 AM IST. Subscribe to receive each issue directly in your inbox, or browse the archive above.
