🔴 Map lines 👇👇
📌 Agonic line:- The line joining the places of zero declination
📌 Aclinic line:- The line joining the places of zero dip
📌 Isogonic line:- The line joining the places of same declination.
📌 Isohypes:- The line joining the points of equal elevation or height.
📌 Isobath:- The line joining the points of equal depth of sea water.
📌 Isobar:- The line joining the points of equal atmospheric pressure.
📌 Isohaline:- The line joining the ocean regions of equal salinity.
📌 Isohel:- The line joining the points of equal period of insolation.
📌 Isohytes:- The line joining the points of equal precipitation.
📌 Isonif:- The line joining the points of equal snow
📌 Isocline:- The line of equal magnetic dip.
📌 Isophyte:- The line joining the points of equal height vegetations.
📌 Isochrone:- The line joining the points of equal time of flow
📌 Isotach:- The line in the weather maps, showing the points of equal wind velocity.
📌 Isorymes:- Lines of equal frost.
💡 Scientific Instrument 👇👇
♦️ Salinometer:- Determine salinity of solutions.
♦️ Sonar:- Used to detect objects under water.
♦️ Stereoscope:- To view two-dimensional picture.
♦️ Tachometer:- A theodolite adopted to measure distances, elevations and bearing during survey.
♦️ Udometer, Pluviometer, Ombrometer, hyetometer :- Rain gauge
♦️ Venturimeter:- To measure rate of flow of liquids.
♦️ Viscometer:- Measures viscosity of liquids.
Instrument used in surveying👇
♦️ Clinometer:- measuring angles of slopes
♦️subtence bar:- measure horizontal distance
♦️Box sextant:- measuring horizontal angle
♦️Planimeter:- measuring area on map
♦️pentagraph:- enlarging or reducing area on map
♦️line Ranger:- ranging a chain line
♦️Hand level:- Making contour & Cross section of preliminary work
♦️Ceylon ghat tracer:- Measuring angles of slopes & setting out grade contours.
♦️ The rainfall in rain gauge is measured everyday at 8:30 AM.
♦️ Raingauge are also called as pluviometer, ombrometer, hydrometer & udometer.
♦️The heighst Raingauge density - Israel
♦️All India forecasts of rainfall are prepared at New Delhi
♦️The water year in India starts from first day of June
📌 Agonic line:- The line joining the places of zero declination
📌 Aclinic line:- The line joining the places of zero dip
📌 Isogonic line:- The line joining the places of same declination.
📌 Isohypes:- The line joining the points of equal elevation or height.
📌 Isobath:- The line joining the points of equal depth of sea water.
📌 Isobar:- The line joining the points of equal atmospheric pressure.
📌 Isohaline:- The line joining the ocean regions of equal salinity.
📌 Isohel:- The line joining the points of equal period of insolation.
📌 Isohytes:- The line joining the points of equal precipitation.
📌 Isonif:- The line joining the points of equal snow
📌 Isocline:- The line of equal magnetic dip.
📌 Isophyte:- The line joining the points of equal height vegetations.
📌 Isochrone:- The line joining the points of equal time of flow
📌 Isotach:- The line in the weather maps, showing the points of equal wind velocity.
📌 Isorymes:- Lines of equal frost.
💡 Scientific Instrument 👇👇
♦️ Salinometer:- Determine salinity of solutions.
♦️ Sonar:- Used to detect objects under water.
♦️ Stereoscope:- To view two-dimensional picture.
♦️ Tachometer:- A theodolite adopted to measure distances, elevations and bearing during survey.
♦️ Udometer, Pluviometer, Ombrometer, hyetometer :- Rain gauge
♦️ Venturimeter:- To measure rate of flow of liquids.
♦️ Viscometer:- Measures viscosity of liquids.
Instrument used in surveying👇
♦️ Clinometer:- measuring angles of slopes
♦️subtence bar:- measure horizontal distance
♦️Box sextant:- measuring horizontal angle
♦️Planimeter:- measuring area on map
♦️pentagraph:- enlarging or reducing area on map
♦️line Ranger:- ranging a chain line
♦️Hand level:- Making contour & Cross section of preliminary work
♦️Ceylon ghat tracer:- Measuring angles of slopes & setting out grade contours.
♦️ The rainfall in rain gauge is measured everyday at 8:30 AM.
♦️ Raingauge are also called as pluviometer, ombrometer, hydrometer & udometer.
♦️The heighst Raingauge density - Israel
♦️All India forecasts of rainfall are prepared at New Delhi
♦️The water year in India starts from first day of June
🔹 Methods of Curing -
1. Curing by spraying water -
Spraying of water continuously on the concrete surface provides an efficient curing. It is mostly used for curing floor slabs. The concrete should be allowed to set sufficiently before sprinkling is started. The spray can be obtained from a perforated plastic box. On small jobs sprinkling of water may be done by hand. Vertical and sloping surfaces can be kept continuously wet by sprinkling water on top surfaces and allowing it to run down between the forms and the concrete. For this method of curing the water requirement is higher.
2. Curing using wet Gunny bags -
This is a widely used method of curing, particularly for structural concrete. Thus exposed surface of concrete is prevented from drying out by covering it with hessian, canvas or empty cement bags. The covering over vertical and sloping surfaces should be secured properly. These are periodically wetted. The interval of wetting will depend upon the rate of evaporation of water. It should be ensured that the surface of concrete is not allowed to dry even for a short time during the curing period. Special arrangements for keeping the surface wet must be made at nights and on holidays.
3. Curing by Ponding Method -
This is the best method of curing. It is suitable for curing horizontal surfaces such as floors, roof slabs, road and air field pavements. The horizontal top surfaces of beams can also be ponded. After placing the concrete, its exposed surface is first covered with moist hessian or canvas. After 24 hours, these covers are removed and small ponds of clay or sand are built across and along the pavements. The area is thus divided into a number of rectangles. The water is filled between the ponds. The filling of water in these ponds is done twice or thrice a day, depending upon the atmospheric conditions. Though this method is very efficient, the water requirement is very heavy. Ponds easily break and water flows out. After curing it is difficult to clean the clay.
4. Steam Curing -
Steam curing and hot water curing is sometimes adopted. With these methods of curing, the strength development of concrete is very rapid.
These methods can best be used in pre cast concrete work. In steam curing the temperature of steam should be restricted to a maximum of 750C as in the absence of proper humidity (about 90%) the concrete may dry too soon. In case of hot water curing, temperature may be raised to any limit, ay 1000C.
At this temperature, the development of strength is about 70% of 28 days strength after 4 to 5 hours. In both cases, the temperature should be fully controlled to avoid non-uniformity. The concrete should be prevented from rapid drying and cooling which would form cracks.
5. Curing using chemicals -
Curing compounds are chemical products usually sprayed directly over the concrete surface and allowing it to dry. The compound forms an impermeable membrane that retards the loss of moisture from the concrete.
1. Curing by spraying water -
Spraying of water continuously on the concrete surface provides an efficient curing. It is mostly used for curing floor slabs. The concrete should be allowed to set sufficiently before sprinkling is started. The spray can be obtained from a perforated plastic box. On small jobs sprinkling of water may be done by hand. Vertical and sloping surfaces can be kept continuously wet by sprinkling water on top surfaces and allowing it to run down between the forms and the concrete. For this method of curing the water requirement is higher.
2. Curing using wet Gunny bags -
This is a widely used method of curing, particularly for structural concrete. Thus exposed surface of concrete is prevented from drying out by covering it with hessian, canvas or empty cement bags. The covering over vertical and sloping surfaces should be secured properly. These are periodically wetted. The interval of wetting will depend upon the rate of evaporation of water. It should be ensured that the surface of concrete is not allowed to dry even for a short time during the curing period. Special arrangements for keeping the surface wet must be made at nights and on holidays.
3. Curing by Ponding Method -
This is the best method of curing. It is suitable for curing horizontal surfaces such as floors, roof slabs, road and air field pavements. The horizontal top surfaces of beams can also be ponded. After placing the concrete, its exposed surface is first covered with moist hessian or canvas. After 24 hours, these covers are removed and small ponds of clay or sand are built across and along the pavements. The area is thus divided into a number of rectangles. The water is filled between the ponds. The filling of water in these ponds is done twice or thrice a day, depending upon the atmospheric conditions. Though this method is very efficient, the water requirement is very heavy. Ponds easily break and water flows out. After curing it is difficult to clean the clay.
4. Steam Curing -
Steam curing and hot water curing is sometimes adopted. With these methods of curing, the strength development of concrete is very rapid.
These methods can best be used in pre cast concrete work. In steam curing the temperature of steam should be restricted to a maximum of 750C as in the absence of proper humidity (about 90%) the concrete may dry too soon. In case of hot water curing, temperature may be raised to any limit, ay 1000C.
At this temperature, the development of strength is about 70% of 28 days strength after 4 to 5 hours. In both cases, the temperature should be fully controlled to avoid non-uniformity. The concrete should be prevented from rapid drying and cooling which would form cracks.
5. Curing using chemicals -
Curing compounds are chemical products usually sprayed directly over the concrete surface and allowing it to dry. The compound forms an impermeable membrane that retards the loss of moisture from the concrete.
Civil engineering full formula book