NAUTRE…. The only source from which we get the
energy like heat and cold including natural materials like stone / soil
containing chemical. We modify / formulate the natural material or by mixing it
with other natural materials to make one more material for the specific use
called products. Nature provides light energy from which other resources like hot,
cold, water, high / low temperature, humidity, moisture will form in the
environment. Products invented from the nature will again use to protect other man-made
creations like house, roads, bridges, industries, etc to from the nature. So it
is very necessary for understanding the effects of nature on the products in
the time frame.. say before / while / after application.
Let see some of the affect of nature on our structures:
For study purpose, I am referring some
of the major types of products in some category as follows:
Tiling & grouting
|
Waterproofing
|
Flooring
|
Concrete repair
|
Polymer
based cementitious adhesives
|
Acrylic cementitious
LAM
|
Cementitious
flooring & screed
|
Cementitious
structural grout
|
Epoxy
based adhesives
|
Acrylic LAM
|
Epoxy
flooring & screed
|
Cementitious expanding
grout admix
|
Furane
based adhesives
|
Crystalline LAM
|
Polyurethane
flooring & screed
|
Polyester resin
anchoring grout
|
Polymer
based non-sanded grouts
|
Elastomeric LAM
|
Cementitious
epoxy flooring
|
Structural epoxy grout
|
Polymer
based sanded grouts
|
PU based LAM
|
Epoxy
based PU flooring
|
PU injection grout
|
Epoxy
based grouts
|
PU based acrylic LAM
|
Epoxy
coating
|
PU injection foam
grout
|
Furane
based grouts
|
Water based epoxy LAM
|
Polyurethane
coating
|
Cementitious polymer
structural mortar
|
Sealers
|
Rubber based SAM
|
Urethane
coating
|
Cementitious micro
concrete
|
Cleaners
|
Polyproline SAM
|
Water
based epoxy coating
|
Shuttering oil
|
|
|
Solvent
based epoxy coating
|
Oil based mould
release agent
|
|
|
Solvent
free epoxy coating
|
Wax based concrete
curing compound
|
|
|
|
Epoxy bonding agent
|
|
|
|
Anti corrosive epoxy
zinc rich primer
|
|
|
|
Non metallic floor
hardener
|
|
|
|
Acrylic copolymer
based admixture for concrete and mortar
|
|
|
|
SBR based liquid
polymer additive for concrete and mortar
|
|
|
|
Integral cement
waterproofing compound
|
|
|
|
Polyurethane joint
sealant
|
|
|
|
Acrylic crack filler
|
|
|
|
Cement based crack
filler
|
|
|
|
Epoxy resin based
adhesive and repair compound
|
Let see how the nature may create the
problems to the products and how it can be overcome:
1. Climate
/ Temperature: Let see at
how much temperature we the different climates and what will be the effect on
the environment.
Temperature °C
|
What might be at this temp
|
How it feels
|
Other points of interest
|
-30 (that is 30 degrees below
zero)
|
Ice, freezer
|
ICE
|
Very cold if you are outside in
this temperature, unbearable to most
|
-10
|
Ice
|
Snow fall
|
Very cold still but bearable if in lots of warm clothes
|
0
|
Water freezes, ice melts
|
Cold
|
Typical coldest average temperature
for UK in winter
|
4
|
Fridge
|
Cold
|
Water has its smallest volume at
this temperature
|
10
|
|
Cold
|
|
15
|
|
Cool
|
|
20
|
Room indoors
|
Warm
|
|
25
|
Warm room
|
Warm to hot
|
Typical maximum temperature for
British summer
|
30
|
Hot day
|
Feeling hot
|
Typical temperature for hotter
countries
|
37
|
Body temperature
|
Very hot
|
This is the average human body
temperature
|
40
|
Washing machine setting for clothes
for normal wash
|
Very hot
|
If you are outside in this
temperature you will feel hot, but more so if humidity is high.
If your internal body temperature reaches this level you are in danger of
death.
|
50
|
|
Extremely hot
|
Not many places get this high in
temperature, and this heat you would need to find shade, drink water and stay
cool.
|
60
|
Washing machine setting for hot
wash
|
Too hot to live in
|
Most bacteria die at this
temperature
|
90
|
Washing machine setting for hottest
wash
|
Too hot to live in
|
Humans cannot survive such high
temperatures
|
100
|
Water boils in the kettle
|
Water in tea maker
|
Water turns to steam
|
1000
|
Lava from a volcano
|
Rising valcano
|
|
1535
|
Melting point of iron
|
Iron plant
|
At this temperature iron will turn
into liquid form, to be used in industrial manufacturing processes
|
2750
|
Boiling point of iron
|
Blast furnace
|
The temperature at which iron boils
and vapourises
|
5500
|
Surface of the Sun
|
THE SUN
|
|
15 000 000
|
Core of the Sun
|
|
a. Cool climate: Applied product can
affected by the ambient temperatures and humidity, both at the high and low
ends of the range. So, to achieve optimal results users of products need to
make some adjustments in normal procedures to allow for these material
properties. In the winter, the combination of cold temperatures and increased
humidity produce one set of conditions which impedes curing, whilst at the
other extreme hot and dry conditions in summer can result in too rapid curing.
1. Cementitious
Products Slow Curing.
2. Efflorescence
affect (Due to increased water residence times as a result of slowed
evaporation, efflorescence can also be increased in cement based products. Efflorescence
is a deposit of water soluble salts from the cementitious components which are
drawn out by the water and then deposit at the surface when the water evaporates.
Premature sealing can exacerbate this effect.
3. Resin
based products - Slow Curing: These products cure by a chemical reaction
between two components and this reaction is slowed or halted by cold conditions.
The viscosity of the resins can also increase making effective mixing difficult.
Water based epoxies can display increased drying times and apparent stickiness
due to decreased rates of water evaporation.
4. Store the products between 5 – 30 Deg C
in the original unopened containers up to the time as specified by the
manufacturer. If climate is too cold, additional polythene sheets shall be used to protect the products.
Let see what does IS 4082 - says about the stacking and storage of construction materials and components at site:
Typical arrangement of powder like materials:
Let see some on-site images:
Take notice of safety labels on containers and ensure safe storage of products site. Always store sheet products standing up-right, on pallets to prevent roll distortion. Keep the product exactly as per the arrow mark – up / down. Solvent based products (including M/T drums stored out of direct sunlight.
Hardener product part, starts freezing at 14 Deg C. Such products need to be warmed to temperature of 40 Deg C and thoroughly mixed before mixing with other components. Do not heat the product for more than 40 Deg C as discoloration and dimerization may occur. Overheating of product, may lead to explosive of pale / can. Vice-versa, such products stored at high temperatures may cause in release of Nitrogen / Carbon / Oxygen gas and viscosity varies.
Resin part materials are of many more kind, so we not just discuss in the open form. It is always better to seek the knowledge from the manufacturer’s how to protect the product and if get affected by the temperature, what shall be the next course of action—if use it how, if not – how to dispose them.
Products shall not be in cold temperature say, below 10 Deg C. Minimum 10 Deg and less than 35-40 Deg C. Use Halogen lights to bring the place temperature to normal temperature condition. Products used at below or above this temperature, the chemical action will be affected and product pot life, setting time, flowability will be affected and accordingly final results may vary.
If not protected properly, lumps may
form in the power part of the product.
Water mixable products shall be used
with normal temperature water or heated water. But, water to be used shall not
have temperature more than 21 Dec C. Use Halogen lights to bring the working
place temperature to normal temperature condition.
Use rapid set adhesives to reduce cure times. Increase the amount of ventilation by the use of fans which will raise the rate of evaporation.
b. Hot climate: Hot climate is useful for slow drying membranes products. However the air must not be supplied by a heater as this can cause cracking and should only be used on floor levelling products after the material has hard cured.
1. Cementitious
Products Premature Curing: The maximum recommended temperature for the use is 35
Deg C and summer temperatures can easily exceed this. Products cure faster in
hot weather due to the increased reaction rate of the components. This means
that flow or working times / viscosity will be reduced, and tile adhesives will
have shorter open times before skinning.
2. Substrate /
surface get hot: Dark coloured surfaces exposed to direct sun on a hot day can
reach 50 to 80 Deg C. Concrete substrates can act as heat sinks and hold high temperatures
after the air temperature has fallen.
3. Rapid
Evaporation and Poor Bonding: Increased evaporation means the water / liquid
part escapes from the applied product before curing reactions have a chance to
complete, resulting in weak bonds. Highly dried out substrates can absorb water
/ liquid from the applied product they can skin at the interface with the
substrate preventing penetration into substrate and reduced bonding strengths.
4. Resin products
Premature Curing & Slumping: Epoxy products can cure very rapidly at
increased temperatures, especially where full packs has been mixed and
generates its own heat of reaction which significantly reduces pot life. These
materials can also become less viscous and slump when applied on vertical
surfaces.
5. Blistering of
Membrane Products: Liquid membrane products can skin rapidly and prevent the
underlying moisture from escaping. If the substrate is impervious, blistering
can occurs or poor bonding may result.
Tips:
Mixing of products
needs to be done quickly using mechanical machines. Arrange air conditioning.
Externally, only work in the cooler morning or late afternoon hours and do not
lay materials in areas exposed to direct hot sun. Use the maximum quantity of water
for mixing as per products TDS. Use cool water drawn from pipes or taps, water not
exposed to the sun. Water chilled by ice can be used, but the ice must be melt
and the temperature should not be below 10 Deg C. Mix small batches of material
and only work on an area that can be covered before initial cure or skinning
occurs. Surfaces can be lightly sprayed with water or covered with damp cloth (get
confirmation from manufacturer). Properly prime the surface to minimise
excessive absorption of moisture, rising pin holes, etc. Products like bondings
shall be re-applied if dries out. Don’t rework on the applied products which is
crossed the initial setting.
During the installation, factor increased drying times between each step in the job. If the daytime temperature is acceptable, but may drop significantly at night, only use products until around midday to allow the material to form an initial set prior to the onset of cold temperatures at night.
2. Humidity:
Resinous (specially solvent products of epoxy and PU) will not bond to the surface applied at high humid conditions.
3. Moisture: The nominal moisture vapour transmission rate of 15gm/m²/24 hours is considered to be the maximum permitted for resilient flooring as per the requirements of AS2870 for dampproofing of floors. Hence we need to maintain the vapour transmission rate well below.
4. Surface nature:
b.Porous surface
c. Non - Porous surface:
d. Damp surface:
e. Weak top surface: Week surface will not have ability to hold the product in position at the chemically curing time of the product. Epoxy and PU like resinous products will have great tensile strength and take the surface layer and peel up. cementitious products, may have initial good bond but in the long time frame, they also will de-bond by taking the week matrix surface.
f. Smooth surface:
5. Chemicals:
This blog is under construction….. will
be finalized very soon.