Question

winter and rainy seasons may well slow the construction down. Please write an essay to summarize the methods which can ensure the construction be finished in time.(minimum 3 pages)

Answer 1

Winters:

Certain works will be adversely affected during low or freezing temperatures. Take brickwork for example — if below freezing, the water content in the mortar may freeze, which will affect the chemical procedure. The resultant mix can fail due to cement and sand pockets being unbounded by the water which is freezing.In addition, frozen water expands, which can cause problems within the brick/block-work. This could result in areas affected in this way being demolished and rebuilt. Disruption to this particularly critical path will impact on the programme, as well as the cost of more mortar, bricks and labour. The same applies to any ‘wet’ trade, so concrete, render and so on are all affected.Solution is whilst we cannot predict temperatures completely, we can anticipate the time of year in which we are at the most vulnerable to cold issues and try to commence the works to avoid this. Focusing on the actual time of year rather than just the individual timings in the programme can mitigate these issues.

Building sites are inherently dangerous and unpleasant environments, made no less so by the onset of winter. The mobility of workers is decreased due to layers of clothing; risk of slipping and sliding is heightened; and the use of gloves is particularly inhibiting. The management of safety on site is all of our concern, and we need to anticipate additional measures to ensure safety as the weather worsens.Let’s also consider productivity during the bad weather — we tend to slow down, lose focus a little, and certainly struggle to maintain full motivation for the day. It would be naïve in the extreme to think that this does not occur on site.Solution is as project manager we can look to mitigate the effects of the winter weather conditions partially by considering programme performance compliance in the builder’s contract. Programme the works to be slightly less productive during the poor weather, and maybe looking for ways to make the site a more motivated and convivial place during the poor conditions.

The onset of shorter hours of daylight also impedes progress unless we mitigate — floodlighting and site heating are essential to ensure full days can be maintained, and as project manager you need to make sure that this is provided during the worst of the winter. While you can incorporate this requirement into the prelims of your contracts, look for the ‘gaps’ between the contractors — if the bricklayers finish up and clear away from site, they will of course take their floodlights with them. The carpenters will bring new ones along, but what happens if they are delayed or there is a problem?Solution is in many cases we may look to provide plant and equipment of this nature as part of the site management, meaning you are not left without floodlighting and heating. There is no perfect solution or answer, but my point is that you consider and debate the issue towards an acceptable solution. We don’t want our sites packing up at 2.15pm every day during January!

Building sites are excellent sources of scrap metal, building materials, high-value items, tools and plant. There are many toe-rags making a living from preying on small building sites for their whole income. Major construction sites with large on-site overheads have budgets and facilities for full-time security, and as such are hard to pilfer from.Our sites are smaller and often with a large number of different organisations and individuals coming and going, rather than one main contractor in possession of the whole site for the duration of the project. The efficiencies and savings we make when doing our own project management are often at the expense of the overheads — security, safety, logistics and neighbourly issues.At this time of year, the increased hours of darkness are an obvious benefit for the thief. The bad weather tends to see sites more unmanned than usual, and the nature of the ‘sub-contractor’ approach makes the presence of a new person on site less noted or worried about by neighbours or passers-by.Budget probably precludes security personnel, but we may look at imaginative means for the fit-out stage when the high-value items are on site. CCTV accessed via the internet is a good means of monitoring the project, but CCTV is often only useful for seeing what has already happened rather than preventing it from happening in the first place.

The management of the programme can be an oblique yet effective means of enhancing security — what may be considered clever programing leads us to getting the superstructure completed during the summer, to avoid winter working outside. We then tend to forget the possible impacts of bad weather as the building is secure and weathered in. So we then get deliveries of high-value items such as kitchens, copper wire, sockets, boilers and the like. The advice at this point is to consider the deliveries to suit the fixing schedule, to avoid these high-value items sitting around tempting fate

Monsoon:

Monsoon is an annual weather cycle. In Indian context, it is a seasonally reversing of wind system characterized by wet summers and dry winters. Thewinds traveling over the Indian ocean towards the north tothe subcontinent during the summer monsoon areassociated with large scale cyclonic activity and causeswide spread rain for about four months. The monsoon annual cycle is not sinusoidal but has a sharp transition atthe beginning of the season termed as onset of themonsoon. Indian Meteorological Department establishedin 1875 maintained long term records for weather. It hasdeveloped specific definition for declaring the onset ofmonsoon in a particular area. In Kolkata, the onset formonsoon in average starts from the second week of Juneand it would continue till the middle of September.Monsoon has a substantial effect on construction planning particularly for coastal areas like Kolkata, India.Construction works like roads and bridges are veryseriously affected during monsoon due to surface runoffand ground water table. In a city like Kolkata, major  proportions of the works are related to buildings whichare also affected substantially because of incessant rains.The baseline schedule is often revised due to monsoon.There is no specific framework or guidelines forincorporating the effect of monsoon in construction planning in India. Indian codes [3] are silent indescribing any formal method for estimating scheduledelay for monsoon. Planners generally depend upon their judgment and experience to account for the scheduleimpact due to monsoon. The procedure does not resultobjective solutions because of variations of the planners’experience. A more rigorous analysis is needed todevelop accurate project plans and budget.

Contractors need to keep an eye on their concrete structures during the rainy season. Rain can affect the surface appearance of concrete as well as the internal strength. When the concrete is between its initial setting time and final setting time, the rain can leave patch marks and pores in the wet concrete. This can disturb the upper layer of the concrete before it can cure properly.

Rain can also affect the internal strength of concrete. If there is consistent and heavy rain for multiple days, the excess water on the concrete can slow down the curing process. This can affect the internal bonds between the concrete particles and make the mixture weaker than intended. Here are some other points to consider when pouring concrete in the rainy season.

1. Extra water in the concrete mixture during the rainy season

If you store your aggregates outside, the rain will make the sand and crushed stone wet. This will add extra water to the concrete mix, so remember to use less water when making a batch of concrete. You will also need to keep an eye on your cement and ensure that no moisture gets into the bags while they are being stored. The cement needs to be stored in a dry environment at all times.

2. Use waterproofing admixtures in your concrete

During the rainy season, consider using hydrophilic crystalline admixtures in your concrete batch. These admixtures react with water and cement to form calcium silicate crystals. The crystals block pores and microcracks in the concrete and prevent water from seeping into the structure. Essentially, they seal the concrete and protect it from excess water damage.

3. Avoid pouring concrete during heavy rains

Make sure that the weather conditions are not too wet or windy before you decide to pour concrete. Keep an eye on the weather forecasts and try to find a gap of at least 12 hours where there is no rain. Fresh concrete needs about 12 hours to start the curing process and any rain could affect this. The wind can also have a negative impact on the curing process. Strong winds can cause bleeding in the concrete and affect the evaporation rate of its internal moisture.

4. Rain can cause delays

It is a well-known fact that rain can affect traffic. This can create delays for the transport and delivery of concrete batches. Suppliers need to keep an eye on the weather and avoid making deliveries during the rain. If this is not possible, then drivers should plan to use alternative routes with less traffic. Any delays in delivery will be costly to the project and will allow excess water to affect the construction site.

5. Use waterproof covers to protect concrete

Plastic sheeting and waterproof canvas should be kept on-site during the rainy season. Once a concrete batch is poured, cover it with the sheeting to shield the concrete from the rain. This will keep moisture in the concrete and keep excess water out. Waterproof covers can also be used to protect aggregates and keep them dry.

6. Perform inspections after the rain

Once the rain has subsided, asses the concrete and see if there is any damage or pools of water on the surface. A simple scratch test can be done to see if the surface of the concrete has been affected by the rain. If there is any surface damage or dimples left by the rain, contractors can use a float to remove excess pools of water and smooth the surface of the concrete at the same time.

The key to ensure the success of a building project during the rainy season is preparation. Be ready for heavy rains and have the right equipment and materials on-hand to deal with the wind and water. Pouring concrete in the rain is not advisable – rather stop and wait for the rain to pass, then remove the surface water in the foundations or on the already-poured concrete before completing the pour.