Concrete

Durable concrete for tunnelling application

Published

14 years ago

July 31, 2012

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In this first part of the two-part series, EugenKleen of Mc-Bauchemie Mueller GmbH and Co.KG spells out the properties required in concrete and the types of concrete used in tunnelling application.Over the decade the use of concrete admixtures, especially plasticizers and superplasticizers, is showing upward trend in India. The advent of concrete pumps and transit mixers has also contributed to this, as the use of superplasticizers enables trouble-free pumping operations and minimizes pipe blockages. With the advent of major metro projects across India, durability of concrete used especially for tunnelling segments is of prime importance. The earlier attitude of taking recourse to the use of admixtures only after facing problems is changing fast, and now, in most tunnelling projects, high performing admixtures are already included in the specifications and the mix is designed to achieve the necessary properties.The concrete for tunnel segments necessitates the concrete to have the following properties:??Compressive strength??Workability??Surface finish??DurabilityAs part of the durability requirements, concrete is or should be generally tested for the following properties:??Chloride migration??Sulfate resistance??Water absorption??Acid resistance??Porosity??Freeze thaw resistanceThis can be achieved using the latest technologies available for concrete. Concrete is now no longer a material consisting of cement, aggregates, water and admixtures but it is an engineered material with several new constituents like PFA, GGBSF, Microsilica, Metakaolin, Colloidal Sillica and several other binders, fillers and pozzolanic materials. The concrete today can take care of any specific requirements under most exposure conditions.The mix designs are getting relatively complex on account of interaction of several materials and mix design calls for expertise in concrete technology and materials. High performance concretes will have to be adapted for tunnelling segments, considering special properties as well as low cost maintenance strategies.What type of concrete do we use?Concrete used in tunnelling applications need the following outstanding properties viz. Compressive strength, high workability, enhanced resistances to chemical or mechanical stresses, lower permeability, durability etc. this will necessitate the use of high performance concrete. Some HPC types which will hold the key for tunnelling applications can be classified into:??Self compacting concrete / high workability concrete??Concretes resistant against aggressive mediaSelf-Compacting Concrete (SCC)Self-Compacting or Consolidating Concrete (SCC), as the name signifies should be able to compact itself by its self-weight under gravity without any additional vibrations or compaction. Self compacting concrete should be able to assume any complicated formwork shapes without cavities and entrapment of air. The reinforcement should be effectively covered and the aggregated should be fully soaked in the concrete matrix. In addition, the concrete should be self-levelling type and self-defoaming without any external compaction.The formulation of self compacting concrete has the latest concrete technology and it requires in-depth knowledge of materials and meticulous testing procedures before the concrete is designated as SCC. Self compacting concrete has the following special advantages.??Saving of cost on machinery, energy and personnel for vibrating the concrete??Considerable improvements to exposed surfaces (Fair Faced Concrete), less efflorescence??Marked improvements in durability on account of better compaction??Extremely suitable for slim and complicated moulds??Covers reinforcement effectively??Better adhesive between cement binder and aggregates??Reduction in de-moulding time??Advantage with respect to sound pollutionTherefore while calculating the costing and economics of self compacting concrete all the above mentioned advantages should be converted to cost parameters. This kind of concrete can give advantage of good compressive strength, workability and finish to the tunnel segments and may prove suitable.Durable concrete resistant against aggressive mediaOne major application of HPC is to increase the durability of concrete where aggressive underground conditions are anticipated. This can be achieved physically by resorting to very dense aggregate packing.Practically possible by selecting a very smooth sieve line from largest aggregate to the smallest grain of mineral additives like microsilica or new generation aluminosilicate slurries. Chemically, cement by itself is not acid resistant. The acid resistant binder is formed by combination of cement, microsilica / aluminosilicate and flyash. To control permeability very low water cement ratio has to be adopted. So as to provide the essential concrete properties a high-performance PCE (polycarboxylate ether) needs to be incorporated in the mix. By adjusting the particle size distribution on the micro scale the permeability of the concrete is reduced which minimizes the penetration of aggressive substances. Depending on the degree of dispersion these material particles more or less completely fill the spaces between the cement particles. During hydration the pozzolanic silica reacts with the free calcium hydroxide to form calcium silicate hydrates. This gives a denser concrete structure.(Source: Paper presented by the author at the Construction Chemicals International Conference 2012 held in Mumbai)

Concrete

HeidelbergCement India Receives Consent For Khandwa Grinding Unit

Consent granted by Madhya Pradesh Pollution Control Board

Published

16 hours ago

May 21, 2026

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HeidelbergCement India (HeidelbergCement India) has received regulatory consent to establish a cement blending and grinding unit at Village Dongaliya, Tehsil Punasa, District Khandwa in Madhya Pradesh. The consent was granted by the Madhya Pradesh Pollution Control Board under the Water (Prevention & Control of Pollution) Act, 1974 and the Air (Prevention & Control of Pollution) Act, 1981 and is dated 17 May 2026. The company disclosed the development in a filing made under Regulation 30 of the SEBI (Listing Obligations and Disclosure Requirements) Regulations, 2015.

The project plan envisages procurement of long term availability of fly ash and the allotment of land on lease for setting up the unit. The proposed facility is described as a blending and grinding installation which will process cementitious materials sourced from nearby operations and suppliers. Company filings state the measures required to secure raw material logistics and statutory compliance before commencing construction.

The addition of a grinding unit in Khandwa is intended to strengthen regional supply and improve logistical efficiency by reducing haulage distances for finished product. The unit is expected to complement existing capacities in central India and to offer flexibility in product mix through blending operations. The reliance on fly ash as a supplementary cementitious material will necessitate long term supply agreements with thermal power producers and coordination with waste utilisation policies.

The disclosure to the regulator and to the stock exchanges follows standard corporate governance practice and aims to keep investors apprised of capital expenditure initiatives. The company indicated that subsequent permits and clearances would be sought in accordance with applicable environmental and land use rules. The project is presented as part of HeidelbergCement India’s broader strategy to optimise capacity distribution and to respond to regional demand dynamics.

Concrete

PROMECON introduces infrared-based tertiary air measurement system for cement kilns

Published

2 days ago

May 20, 2026

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The new solution promisescontinuous, real-time tertiary air flow measurement in cement plant operations.

PROMECON GmbH has launched the McON IR Compact, an infrared-based measuring system designed to deliver continuous, real-time tertiary air flow measurement in cement plant operations. The system addresses the longstanding process control challenge of accurate tertiary air monitoring under extreme kiln conditions. It uses patented infrared time-of-flight measurement technology that operates without calibration or maintenance intervention.

Precise tertiary air measurement is a critical requirement for stable rotary kiln operation. The McON IR Compact is engineered to function reliably at temperatures up to 1,200°C and in the presence of abrasive clinker dust. Its vector-based digital measurement architecture ensures that readings remain unaffected by swirl, dust deposits or drift. Due to these conditions conventional measurement systems in pyroprocess environments are often compromised.

The system is fully non-intrusive and requires no K-factors, recalibration or periodic readjustment, enabling years of uninterrupted operation. This design directly supports plant availability and reduces the maintenance overhead typically associated with process instrumentation in high-temperature zones.

PROMECON has deployed the McON IR Compact at multiple cement facilities, including Warta Cement in Poland. Plant operators report that the system has aided in identifying blockages, optimising purging cycles for gas burners, and supplying accurate flow data for AI-based process optimisation programmes. The practical outcomes include more stable kiln operation, improved process control, and earlier detection of process disturbances.

On the energy side, real-time tertiary air data enables reduction in induced draft fan load and helps flatten process oscillations across the pyroprocess. This translates to lower fuel and energy consumption, fewer unplanned shutdowns, and a measurable reduction in NOx peaks. This directly reflects on the downstream cost implications for plants operating SCR or SNCR systems for emissions compliance.

Concrete

Adani Group To Set Up Cement Factory In Madhya Pradesh

Chief Minister Mohan Yadav inaugurates plant in Guna

Published

4 days ago

May 18, 2026

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Adani Group (Adani) will set up a cement factory in Madhya Pradesh, the chief minister of the state announced after an inauguration ceremony in Guna. The chief minister, Mohan Yadav, described the occasion as a historic day for the state and said the project will strengthen industrial capacity. The event was presented as a milestone in efforts to broaden manufacturing and attract large-scale investment. Officials said the facility will add to regional production capability and support related industries.

State officials outlined that the plant will enhance supply chains for construction and infrastructure projects across the region. The company will bring technical expertise and logistical resources to the site, with government agencies coordinating approvals and land allocation. Local suppliers and service providers will benefit from increased demand, and training initiatives will be developed to build workforce readiness. Officials indicated that the project complements broader plans to modernise industrial clusters in the state.

The state administration said it has facilitated clearances and infrastructure support to accelerate implementation. Local officials have coordinated with the company to ensure connectivity and utilities are in place ahead of commissioning. The chief minister emphasised that collaboration between private investors and the government aims to create sustainable economic growth. Community outreach programmes will address local concerns and establish grievance mechanisms as construction proceeds.

Officials said the inauguration in Guna marks a new phase in the state industrial story and will serve as a reference for future investments. Administrators noted that close monitoring and periodic reviews will guide timely execution and adherence to environmental and safety norms. The government affirmed its commitment to facilitating responsible industrial expansion while ensuring benefits reach local communities. Stakeholders will continue discussions on supply chain integration and long term maintenance arrangements.