Girish Nair
Zonal Manager (South)
Mapei Construction Products India Pvt. Ltd. www.mapei.com
Life expectancy is not just a term associated with a living, breathing being but even with an immobile non-living element, like a building. According to researchers, the general lifespan of a concrete building lies in the average range of 75 to 100 years and for a residential building, this can be even close to 40 years. By which time, complete deterioration can happen in the absence of building maintenance.
In this article, we shall discuss about repair of a residential building which is 40 year old using Mapei products and also listing of Mapei products that can be used for different type of maintenance of a building.
Each building, early deterioration of a building can occurs due to:
⦁ Poor design, detailing and construction
⦁ Severe environmental actions
⦁ Substandard construction materials
⦁ Unintended use
⦁ Poor management
Repair Of A Residential Building
Ground floor of a residential building which is 40 year old had deteriorated very badly and had one more floor with people living in it. The ground floor was damaged due to water seepage and bad maintenance. This house was to be repaired without damaging the first floor. The risk of crack and damage to the first floor was high. The damaged house had water seepage, no maintenance and usage of substandard construction materials.
Mapei offers wide range of repair products but due to budget constraints the following products were used for repair of the referred house.
Fig. 1: Shows the Damage of the House with Big Holes where the Termites had Damaged the Bricks
Fig. 2: Shows Treated Wall with Mapegrout T40 and Application of Planiseal 88
Fig.3: Smooth and even Wall using Mapewall Ready Mix Plaster
Fig. 4: Completed Wall
Conclusion
‘Better Safe than Sorry’ Following good construction practices and using construction chemical products during the construction of a residential
building give more life span and low maintenance cost.
Acknowledgement
The author thanks Mr. Chandrakanth Kamath and Mr. Jackson for the inputs of the residential building and photographs
Amol Popli
Head Sales (Restofix)
STP Limited www.stpltd.com
The deterioration of reinforced concrete structures is recognized as a major problem worldwide. Today, concrete repair is a major industry supporting the needs of virtually every concrete structure.
Each structure requires routine repair and maintenance, ranging from simple protective coatings to repair of spalling to strengthening of under-designed components. Apart from requiring regular maintenance, many structures require extensive Repair, Rehabilitation & Retrofitting.
Though concrete is quite strong mechanically, it is highly susceptible to deterioration and thus gets damaged & even fail ultimately, unless some measures are adopted to counter deterioration. Such deteriorated structures can be rehabilitated and retrofitted by using various types of modern repair materials and techniques.
STP Limited provides Restofix range of concrete repair materials manufactured to restore and repair damaged or sub-standard concrete by providing structural and non-structural repairs, in addition to sealing and bonding cracks through injections.
Understanding Deterioration And Corrosion
The durability advantage of cement concrete is a major reason why it is the world’s most widely used construction material.But material quality, design and construction practices, and severe exposure conditions can cause concrete to deteriorate, which results in aesthetic, functional or structural problems.
Generally, concrete deterioration is gradual; and, depending on their service and environment, steel-reinforced concrete structures can stand for decades before the onset of steel corrosion. Concrete can deteriorate for a variety of reasons, and concrete damage is often the result of a combination of factors.
Although concrete is porous in nature and the structure contains moisture and oxygen, due to its high alkalinity, the cover concrete surrounding the reinforcements, form a protective, passive oxide layer on the reinforcing steel that reduces the corrosion rate to a negligible level.
For reinforcing steel to corrode, the passive oxide layer on the steel must fail. If the concrete cover that protects the reinforcing steel is damaged and the bond between the concrete and steel reinforcing bar is broken, the steel’s passive layer will break down and active corrosion of the steel will start. There are two mechanisms, however, that will damage the passive layer on the steel reinforcement, even if the concrete cover is not damaged: chloride ions and carbonation. This makes the steel vulnerable to corrosion.
Steps For Concrete Repair And Maintenance
Before commencing any repair work, it is necessary to carry out thorough inspection and evaluation, identify the root cause of the deterioration and accordingly a repair methodology to be prepared and followed. An incomplete or incorrect evaluation may lead to decide on carrying out only surface repairs without addressing the root cause of deterioration. Eventually, the repair work will lead to failure and re-occurrence of the damages.
Accordingly, there are seven basic steps for concrete repair and maintenance:
⦁ Determine the cause(s) of damage
⦁ Evaluate the extent of damage
⦁ Evaluate the need to repair
⦁ Select the repair method and material
⦁ Prepare the existing concrete for repair
⦁ Apply the repair method
⦁ Cure the repair properly
In these steps, the choice of procedure, surface treatment and materials for concrete repair will depend on the existing degree of deterioration, the mechanism of deterioration, its causes and anticipated future service requirements.
Principles And Solutions For Sustainable Concrete Repair
The phases of repair projects follow a logical sequence, which is dominated by engineeringaspects. Depending upon the sequence of repair for a concrete structure, the above Table shows the Product Segments, Product Details, Product Description and Area of Application. The product details mentioned are to address theneed for protection and repair of concrete and to prevent damages due to reinforcement corrosion, respectively.
STP’s Restofix range of products for concrete rehabilitation includes ShaliFix polymer modified structural mortars and micro-concretes designed for replacing the strength of concrete lost due to degradation. The ShaliFix range incorporates active corrosion inhibitors to ensure the integrity of steel reinforcement for many years after repair. Restofix also includes coatings for corrosion protection of steel reinforcements, anti-carbonation coatings for concrete to allow completion protection of structure of the project.
STP’s Restofix range provides ShaliProtek coatings and protection systems and our ShaliWrap carbon and glass fibre and ShaliLam carbon laminates strengthening system.
STP Limited combines these materials to create engineering solutions that repair and extend a structure’s useful life by preventing further damage and to return the structure to original or upgraded service requirements.
Agenda 111’, the project including 101 district hospitals, ten regional hospitals and the renovation of Effia-Nkwanta Regional Hospital will be undertaken in Ghana and as per Ghanaian Ministry of Health, sites have been secured for 88 of 101 district hospitals, each to cost some $17m with a campus covering 15 acres.
The hospitals’ blueprint incorporates centuries-old Ghanaian Adinkra symbols and the designs are inspired by the Denkyem, a famous species of tiny crocodiles in Kenya.
Adjaye Associates comments in a press release, “By approaching the hospital as more than just a place for the provision of medical services, the design scheme aims to unlock the potential of this ambitious initiative by repositioning the hospital as a piece of community infrastructure that embodies sustainability, efficiency, and generously provides green spaces to facilitate wellness and healing.” Ghana’s Ministry of Health estimates that the first hospitals will be finished within the next year.
The City of Prague reported that it is preparing to convert slag produced from the incineration of waste into building materials. According to Hlubuček, the incinerator produces 65 to 70 thousand tons of slag annually and the city pays approximately CZK 40 million (EUR 1.5 million) a year for land filling.
This waste can now be converted into raw materials and used in the construction industry. More specifically, clean slag reportedly has various useful properties which would allow it to be utilized as a base layer in the construction of roads.
Hlubuček discussed the advantages of this initiative, stressing that it would result in great financial savings and a reduction of CO2 emissions and would help bring the capital closer to achieving its climate goals.
The first 3D printed steel bridge in the world – an innovative project headed by Dutch company MX3D, opened to the public in Amsterdam. The novel landmark spans one of the city’s oldest canals and sits in the center of the red-light district.
The 40-foot-long bridge doubles as a ‘living laboratory’ with hidden sensors that collect real-time data about the overpass’ performance. Researchers at Imperial College London will use this data to analyze how the bridge reacts over time as pedestrians interact with it.
“A 3D printed metal structure large and strong enough to handle pedestrian traffic has never been constructed before,” says Leroy Gardner, a structural engineer at Imperial, in a statement. “It’s fantastic to see it finally open to the public.”
As Mark Girolami, a civil engineer at the University of Cambridge who is working on the digital model, tells New Scientist’s Matthew Sparkes, bridge failures can often be attributed to overlooked deterioration. By constantly transmitting data about a bridge’s status, 3D printed versions may be able to provide early warnings and prevent collapses.
