Connect with us

Concrete

Assessment of structures

Published

on

Shares

All civil engineering structures are initially designed depending on certain design criteria, such as design loads, allowable stresses etc. But, damage due to an extreme event is always possible in a structure during its design life. Sometimes, undetected and un-repaired damage may lead to structural failure demanding costly repair and a huge loss of lives. Therefore, the problem of maintenance and repair of existing engineering structures involves damage detection at an early stage.

For massive structures like bridges, dams, flyover, ROB, RUB, chemical plants, thermal and nuclear plants, silos, pre heater towers, chimneys, etc., which were constructed some 20-40 years ago, it is necessary to test its functionality under the present load situation and quantify damage if any. Since it involves huge expenditure to demolish and reconstruct them, it is important to evaluate the residual life-RLA (residual life analysis) of these structures.

Performing NDT of concrete structures, which is a basis for the evaluation of RLA/remnant life analysis ??RLA studies. Many methods are traditionally used for flaw characterisation and measurement of residual stress. Combining these inputs many parameters, including mechanical properties, factor of safety in design, conservative operation of unit, inaccuracy in data extrapolation, overestimation of corrosion effects, etc., would be assessed.

Damage Detection and Condition Assessment of Civil Structures

In the assessment of existing structures, engineers are increasingly faced with not only the challenges of early detection of damage, but also the evaluation of structure performance and behavior under damage, and economical and efficient retrofitting of the damaged components commonly found in older structures. In order to maintain the safety and integrity of structures, research on the damage mechanism, assessment of structure performance in damaged status, and innovative technologies and materials to rehabilitate, repair, and retrofit structures are of great significance.

Retrofitting of a cement Plant Preheater Tower

Inspection by plant personnel revealed cracking in the concrete frame of a 326-ft-tall, 7-level preheater tower. Onsite plant engineers deemed the cracking significant, especially since the structure supports critical manufacturing process equipment. A structural engineering consulting firm was retained to evaluate the extent of the problem and formulate a repair plan on a fast-track basis. The firm mobilised at the site in less than 24 hours and performed an initial structural safety assessment. A comprehensive structural evaluation indicated that the structure required strengthening. Restoration consultants were engaged to assist locally with engineering and construction administration.

A specialty repair contractor also was engaged to review the constructability of several alternate repair schemes and maintain the fast-track schedule. After considering structural capacity and serviceability requirements, durability issues, the high-temperature operating environment, constructability, and an aggressive construction schedule, the team recommended a retrofit consisting of bonded post-tensioning within internal holes drilled in the beams. This solution was quite extraordinary, as it required precision-drilling horizontal holes up to 87 feet long in the beams of the elevated frame structure, without cutting existing embedded reinforcement.

Nondestructive impulse radar testing was used to locate existing embedded reinforcing steel, as well as to monitor the drilled holes’ trajectory. This process helped ensure proper hole alignment and prevent damage to embedded steel. The cored holes served as post-tensioning ducts. The repairs were executed on a fast track basis and under challenging circumstances, which included working high on the exposed structure through a cold winter with severe wind conditions. The unique retrofit resulted in a structure that is stronger, more serviceable, and more durable than the original tower. The project represented an exceptional team effort, and its success is attributable to the leadership of the owner and client, the ingenuity of the engineering team, and the resourcefulness of the contractor.

Case study authored by: Kolf, Peter R, Oesterle, Ralph G

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Concrete

Cement Prices To Hold Steady Amid Monsoon Slump

Centrum report says demand weakness will limit hikes

Published

on

By

Shares

Centrum, a financial services firm, has reported that cement prices are likely to remain largely unchanged in July as weak demand during the monsoon season constrains pricing power. The report noted that construction activity remained subdued in the first quarter of fiscal year 2027 owing to labour shortages and slower execution of government projects. While June showed some volume recovery driven by delayed monsoons and quarter end sales, dealers are cautious about sustaining any price increases.

The analysis suggested that seasonal slowdown related to monsoon will prolong demand and pricing challenges through the second quarter. Dealers saw most recent attempts at price hikes as protective measures rather than genuine shifts in market fundamentals. They signalled that pockets of demand in select regions could prompt isolated adjustments but that broad based increases were unlikely while construction activity remained weak. Market participants therefore expected a cautious stance on pricing.

The report highlighted that despite intermittent recovery in shipments during June, the underlying demand trajectory remained muted as monsoon hampered site level activity and logistics. Commercial builders and retail dealers both reported constrained order books and slower payment cycles, which in turn reduced room for margin expansion among manufacturers. Analysts noted that unless government project execution accelerates markedly, demand improvement would be gradual. Price setters were thus likely to focus on protecting market shares rather than pursuing aggressive increases.

Market watchers said the near term outlook would be shaped by monsoon progress and fiscal spending patterns, with any acceleration in public works offering the most tangible support. Traders expected that regional variations would persist and that trade flows between surplus and deficit centres would determine local price movements. The report concluded that stakeholders should prepare for a period of subdued pricing until demand signals strengthen.

Continue Reading

Concrete

Cement Prices Set To Stay Under Pressure In July

Monsoon and weak demand keep prices under strain

Published

on

By

Shares

A report by Centrum said cement prices are expected to remain largely flat in July as the monsoon and weak demand weigh on the sector. The report said demand during the first quarter of FY27 remained range-bound and below expectations, with dealers across markets pointing to subdued construction activity, labour shortages, elections, heatwaves and slower execution of government projects as key reasons. It noted that some recovery was witnessed in June due to delayed onset of the monsoon and quarter-end volume push.\n\nDealers across most markets do not expect any meaningful price increases in July, the report said, adding that attempts to raise prices in some markets are aimed at defending existing levels rather than achieving significant gains. The sharp correction following the rollback of April hikes has largely played out across most regions, limiting scope for further immediate increases. Seasonal slowdown in construction activity during the monsoon is expected to continue affecting demand and pricing in the coming months.\n\nCentrum indicated that pricing pressure is likely to persist through the second quarter of FY27 as monsoon-related softness continues. Dealers remain cautious about sustainability of any price rise attempts and do not rule out further weakness during the peak monsoon period. The combination of subdued demand and seasonal factors is likely to constrain the industry’s ability to raise prices in the near term. While June saw some improvement in volumes because of delayed rains and quarter-end sales efforts, the broader demand environment remains challenging.\n\nCement companies are therefore expected to focus on maintaining current price levels rather than pursuing aggressive increases as the sector navigates weak demand and seasonal headwinds. The report suggested that unless demand conditions improve significantly, limited scope will exist for meaningful price recovery. Market participants remain watchful for any shifts in execution of infrastructure projects or construction activity that could alter the outlook.

Continue Reading

Concrete

TARIL Secures Ultra Mega Transformer Order From PGCIL

Order for manufacturing transformers to be delivered in 30 months

Published

on

By

Shares

Transformers and Rectifiers (India) Limited has received Notifications of Awards from Power Grid Corporation of India Limited (PGCIL) for multiple contracts to manufacture transformers and undertake associated works. The company submitted the disclosure to BSE and the National Stock Exchange under Regulation 30 of the SEBI Listing Regulations. The submission cited security code 532928 and trading symbol TARIL, and the filings cite the award reference and confirm execution in accordance with the terms and conditions stipulated in the notifications.

The contracts are described as an Ultra Mega Order under the company classification, indicating a value at or above Rs 10 billion (bn) on conversion. The filing identifies the contracts as domestic orders and specifies a scheduled delivery period of 30 months. The scope covers manufacturing of transformers of various ratings together with all associated work. The order size places it in the highest project classification defined in the company’s disclosure.

The disclosure states that the promoter group and group companies have no interest in the awarding entity and that the contracts do not constitute related party transactions. The company noted that the awards will be executed in the normal course of business and not fall within related party transactions. The document reiterates that the company is committed to delivering high quality products and services and has established itself as a leading manufacturer of transformers in the country over time.

Chief Financial Officer Mehul Shah authorised the filing and requested the exchanges to take the information on record, with the company providing the requisite filing reference in its submission. The company indicated that the orders will be executed as per the notifications of awards and the applicable regulatory framework. The original filing is available on the stock exchange portal at the provided link.

Continue Reading

Video Thumbnail

    SIGN-UP FOR OUR GENERAL NEWSLETTER


    Trending News