Basic Concepts Required at Site

 Check List for Civil Engineer

Civil engineers design projects that are most efficient and capable in a real world setting. While they try their best to perfect each design, some mistakes may arise in their design plans. Therefore, projects have design review checklists to ensure thorough review of all project documentation. These checklists cover all aspects of a typical civil engineer project. Here are seven of the common items on a civil engineer’s design review checklist.

                                                             CENTIMETER:-

                                                                                                         1 Centimeter = 0.3937 inches

        1 Centimeter = 0.032808 feet

                                                                                                         2.54 Centimeter= 1 inch

                                                                                                         30.48 Centimeters = 1 Foot

                                                                                                         91.44 Centimeters = 1 yard

                                                                                                         1 karam = 5.5 feet

                                                                                                         1 karam = 1.67 meter

                                                                                                         1 square Karam =  30.25 square feet

                                                                                                         1 square Karam = 2.679 meter square

FEET OR METERS:-  

1 Feet = 12 inches

1 Feet = 0.3048 meter

1 Feet = 0.0929 meter square                             
         

1 Inch = 25.4 mm

1 Meter = 1,000 mm

1 Meter =3.281 feet

1 Meter = 1.094 yard

1 Meter Square = 10.764 square feet

Sometimes we will get a material calculation completely different from their original unit. Like getting cement quantity in m³. But we will buy cement in kgs from the market.

By understanding the unit of materials, we can easily eliminate the estimation barriers in a matter of seconds.

Don’t underestimate this table

Unit Weight of Materials Used at Construction Site

S.No	Material	Theoretical Weight in(KG/M³)	Approx Weight at Site in		Remarks
			Kg	Per
1	Cement	1440	50	Bag
2	Steel	7850	d²/162		d -dia in mm
3	Sand-
	Dry	1600	50 to 55	farma	1 farma=1.25cft
	River	1840	57 to 63	farma	1 farma=1.25cft
4	Stone(basalt)	2850 to 2960	48 to 52	farma	metal 12mm to 20mm
5	Water	1000	1	liter
6	PCC	2240	8.24 to 8.5	Cube mould	cube mould size=15x15x15cm
7	RCC 2% Steel	2420
8	Bricks	1600 to 1920	1.9 to 2	no	9x4x2 3/4″
			4.8 to 4.9	no	9x6x3 3/4”
9	Brick Masonry	1920
10	Soil(damp)	1760	50 to 55	cft	Black cotton
11	Cement concrete block(solid)	1800	18 to 20	cft	30x15x20 cm
			10 to 11	no	30x10x20 cm
12	Cement Mortar	2080	57 to 62	cft
13	Lime Mortar	1760	48 to 52	cft
14	Lime	640	30	bag
15	Glass	2530	0.9 to 0.95	sft	4mm tk plain
16	Teak Wood	670 to 830	18 to 20	cft
17	Sal Wood	990	22 to 24	cft
18	Marble mosaic tile		2.8 to 3.2	no	25x25x22mm
			4.8 to 5.2	no	30x30x25mm
19	Chequered tile		2.5 to 2.8	no	25x25x22mm
20	Glazed tile15x15cm		0.20 to 0.25	no	5mm tk
21	Marble Stone	2620	5.1	sft	3/4″tk
22	Granite Stone	2460-2800	5.35	sft	3/4″tk
23	Coddappa	2720	6.4	sft	1 1/4″tk
24	A.C.sheet corrugated	16	1.2	sft
25	Bitumen	1040	220	Drum	200liter drum
26	Window frame (simple design)		1.9 to2.1	sft
27	Door Frame
	a)3’00×7’0		25 to 27	no	section 4″x2 1/2″
	b)2’6″x7’0		24 to 26	no	section 4″x2 1/2″

Concrete Mix Ratio

The concrete mix ratio is the proportion of its ingredients like cement, sand, aggregate, and water. These mix ratios are defined based on the type of construction and required strength.

Although the IS Code gives nominal and standard mix ratio for different construction work based on experience and testing.

Grades of concrete mainly classified in three categories as follows 

i) Lean concrete ii)  Ordinary grade of concrete iii) Standard grade of concrete iv) High strength concrete grades 

LEAN CONCRETE

Lean concrete is a mix where the amount of cement is lower than the amount of liquid present in the strata.

M5 GRADE

Where M stands for Mix ration & 5 stands for  compressive strength of a 150mm cube after 28 days of curing, expressed in N/mm2

Mix ratio is  1:5:10 (1 Cement, 5 Sand and 10 Aggregate)

Application/use:-  To provide the uniform surface to the foundation concrete and to prevent the direct contact of foundation concrete from the soil.

M7.5 GRADE

Mix ratio is  1:4:8 (1 Cement, 4 Sand and 8 Aggregate)

Application/use:-  To provide the uniform surface to the foundation concrete and to prevent the direct contact of foundation concrete from the soil.

ORDINARY GRADE OF CONCRETE

M10 GRADE

Mix ratio is  1:3:6 (1 Cement, 3 Sand and 6 Aggregate)

It is used as PCC (Plain Cement Concrete)

Application/use:- It can be used in construction of Levelling course, bedding for footing, concrete roads, etc.

M15 GRADE

Mix ratio is  1:2:4 (1 Cement, 2 Sand and 4 Aggregate)

It is used as PCC (Plain Cement Concrete)

Application/use:-  It can be used in construction of Levelling course, bedding for footing, concrete roads, etc.

M20 GRADE

Mix ratio is  1:1.5:3 (1 Cement, 1.5 Sand and 3 Aggregate)

It is used as RCC (Reinforced Cement Concrete)

Application/use:- It can be used in construction of Slabs, beams, columns, footings, etc. (for mild exposure)

STANDARD GRADE OF CONCRETE

M25 GRADE

Mix ratio is  1:1:2 (1 Cement, 1 Sand and 2 Aggregate)

Its is used as RCC (Reinforced Cement Concrete) 

Application/use:- It can be used in construction of Slabs, beams, columns, footings, etc.

Roles And Responsibilites of the Site Engineer

A Site Engineer is very essential for a construction project. The responsibilities of a site engineer are wide as he must provide sufficient advice and supervision when there are any technical issues, or for proper management and for the preparation of day to day reports of the construction works.

A Site Engineer within the construction industry is part of the site management team and acts as day-to-day manager on a construction site, which can include liaising with third party stakeholders and managing the site facilities.
Site Engineers are also responsible for planning, technical queries, marking out and leveling construction sites before any work takes place as well as checking drawings, quantities and ensuring calculations are accurate.
As a Site Engineer you may also share responsibility for health and safety, security as well as organising and supervising people and materials on site.

Site Engineer:-

1. Responsibilities :-

• Organizing materials and ensuring sites are safe and clean.
• Preparing cost estimates and ensuring appropriate materials and tools are available.
• Providing technical advice and suggestions for improvement on particular projects.
• Diagnosing and troubleshooting equipment as required.
• Negotiating with suppliers and vendors to ensure the best contracts.
• Authorizing technical drawings and engineering plans.
• Drawing up work schedules and communicating any adjustments to crew members and clients.
• Gathering data, compiling reports, and delivering presentations to relevant stakeholders.
• Delegating tasks and scheduling meetings and training sessions where required.
• Completing quality assurance and providing feedback to the team.

2.  Skills:-

• Management skills – from the safety of the construction site, to the workforce, materials and strict project timescales, site engineers manage a variety of different elements in the execution of a project.
• Problem solving – unforeseen problems are likely to arise, so you need to be able to quickly and effectively overcome difficulties to avoid missing deadlines.
• Negotiation skills – in order to maximise profit, site engineers should be able to negotiate the best prices for materials.
• Understand relevant building and health and safety legislation.
• Team work, communication and organisation – with so many different people working on the same project, the project is certain to fail without effective team work and organisation.
• Writing and analytical skills – site engineers are required to often produce progress reports so need to have competent written skills.
• Physically fit – site inspections can be physically demanding (climbing ladders, for example), so engineers need to be mobile and have a reasonable level of fitness.

                                         

Tolerance limits in construction work on site

Tolerances in construction are generally a variation in a dimension, construction limit, or physical char- acteristic of a material. They are a practical variation related to the function of the material or finished work and commonly accepted standards of the construction industry.

 In construction all work outside these limits is liable to rejection. The following table gives permissible deviations in the tolerances on construction

Shuttering

	Description	Permissible Deviation
	Deviation from specified dimensions of cross section of columns and beams	-6 mm +12 mm
	Deviation from dimensions of footings
	Dimensions in plan	-12 mm +50 mm
2.	Eccentricity	0.02 times the width of the footing in the direction of deviation but not more than 50 mm
3.	Thickness	+0.05 times the specified thickness
	Departure from level shown on the drawing	6 mm
	Deviations Abrupt irregularities/offsets caused by displaced or misplaced form work lining or supports	3 mm
	Inserts Variations in the position along concrete surfaces In plane position (flush with concrete face)	10mm 6 mm

Note:

• These tolerances apply to concrete dimensions only, not to positioning of vertical reinforcing steel or dowels.
• The formwork shall be capable of being dismantled and removed from the cast concrete without shock, disturbance or damage.
• The arrangement shall be such that the soffit forms are properly supported on props, can be retained in position for such period as may be required by maturing conditions or specifications.

Measuring equipment accuracy in Batching plant.

• Cement : + – 2%
• Aggregate : + – 3%
• Admixture : + – 3%
• Water : + – 3%
• Mixing time : 2 minutes for one mixing. (Mixing which is being done on site)

Tolerance for cutting Length

•  When Specified length is not given = + 75 mm (or) – 25 mm
• When minimum length is specified = + 50 mm (or) – 0 mm