Sanjer Bela Civil Engineering Site

what is soundness in cement! What is Soundness? Soundness is the property of cement that ensures it maintains its volume after hydration and setting, without significant expansion or contraction. 

Q) what is cement in construction? What is Cement? A  cement  is a  binder , a  chemical substance  used for construction that  sets , hardens, and adheres to other  materials  to bind them together.   Types of Cement Cement can be categorized into two main types – hydraulic and non-hydraulic cement.  Hydraulic cement is formed by the reaction of powdered cement with water. You can use it for all types of construction, including underwater construction projects. Non-hydraulic cement sets and becomes adhesive due to carbonation. You can use it for various construction projects, except underwater construction projects.  Hydraulic cement is the most commonly used cement. Portland cement is a type of hydraulic cement that’s been a preferred choice for architects, engineers, and constructors. The primary reason behind its popularity is its ability to harden quickly.   Ordinary Portland cement (OPC) When Portland c...

  Advantage and disadvantage of RCC Advantage 1) Strength :- Rcc has very good strength in tension as well as compression. 2) Durability :- Rcc structures are durable if designed and laid properly. They can last upto 100 years. 3) Mouldability :- Rcc section can be given in any shape easily by properly designing the framework.  4) Ductility :- The steel reinforcement imparts ductility to the rcc structures. 5) economy :- Rcc is cheaper as compared to steel as prestressed concrete. 6) Transporation: - the raw materials which are required for rcc i.e. cement ,sand, aggregate, water, and steel are easily availableand can transported easily. Now a days Raidy mix concrete is used, 7) Fire resistance :- Rcc structures are more fire resistant than other commonly used construction materials like steel and wood. 8) Permeability :- Rcc is almost impermeable to moisture. 9) seismic resistance :- Properly designed Rcc structures are extremely resistant to earthquakes. Disadvantages 1) ...

1)      Comparison of working stress method and limit state method. Working Stress Method  This method is based on the elastic theory which assumes that concrete and steel are elastic and the stress strain curve is linear for both. Limit State Method  This method is based on the actual stress strain curves of steel and concrete. For concrete the stress strain curve is nonlinear. Working Stress method In this method the factor of safety are applied to the yield stresses to get permissible stresses. Limit State Method In this method partial safety factors are applied to get design values. Working stress Method No factor of safety used for loads. Limit state method Design loads are obtained by multiplying partial safety factors of loads to the working loads. Working Stress method Exact margin of safety is not known. limit state method Exact margin of safety is known. Working stress method This method gives thicker so less economical. Limit state method This me...

 A simply supported beam of span 5 m carries two point loads of 5 kn and 7kn as shown in fig . Draw SFD and BMD showing the important values. MA = 0 5*1.5+7*3.5-RB=0 RB = 0.4 KN FY =0 RA+RB-5-7 = 0 RA+6.4-12 =0 RA = 5.6 KN SF BETWEEN A AND C = 5.6 KN OR, 5+7-6.4 = 5.6 KN 2) SF BTWN C AND D = 5.6 -5 = .6 KN OR 7-6.4 = .6 KN 3) SF BTWN D AND B 5.6-5-7=-6.4KN OR  -6.4 KN BM CALCULATION BM AT PNT A = 0 OR, -5*1.5-7*3.5+6.4*5 = 0 2) BM AT PNT B = 0 OR 5.6*5-5*3.5-7*1.5=0 3) BM AT POINT C = 5.6 *1.5=8.4 KN/M OR, -7*2+6.4*3.5 = 8.4 KN/M BM AT D = 5.6 *3.5-5*2 =9.6KN/M OR  6.4*1.5 = 9.6 KN/M

 Find the force in all the members of the truss shown by the method of joint MA = 0, 60*2-RD*4=0 =120 - RD*4 =0 RD = 30 KN Fy = 0, RAV +30 -60 = 0 RAV = 30 KN  fy =0 FAB sin60 = -30 FAB = -34.641 KN(C) FX = 0 FAF +FAB cos60 =0 FAF - 34.641 cos60 =0 FAF -17.32 kn (T) FBD of Joint F Fx = 0  FEF - FAF =0 FEF = 17.32 KN (T) FBD OF JOINT B FY = 0 -FBESIN60-FABSIN60-FFB =0 -FBESIN60-(-34.641SIN60)-0=0 -FBE SIN60=-34.641SIN60 FBE = 34.641KN(T) FX = 0 FBC + FBE COS60 - FAB COS60=0 FBC + 34.641 COS 60+34.641 COS60=0 FBC+34.641=0 FBC = -34.641 KN(C) DUE TO SYMMETRY OF STRUCTURE FCD = FAB FGD=FAF FGE=FEF FCG=FFB FCE=FBE

  As per IS 456:2000, the total deflection due to all loads including   effects of temperature, creep and shrinkage should not exceed span/250.  

  The maximum shear stress (τc,max) in concrete of a reinforced cement concrete  beam depends on grade; for example, for M20, it is 2.8 N/mm². (Refer Table 20, IS 456:2000)

  Partial safety factor for steel as recommended in  IS:456 -2000 for Limit State Method is 1.15.

  The toe projection of foundation slabs is taken  as minimum 150 mm or 1/5th of the depth of foundation, whichever is more (depends on site conditions, often approx. 1/3rd to 1/5th of footing width).

  An R.C.C. column is treated as long if its slenderness ratio is greater than  12 .

  The value of the maximum strain in concrete under bending compression in outermost fibre, as per IS 456:2000 (Limit State Method),  is 0.0035 .

  An R.C.C. roof slab is designed as a two-way slab if  the ratio of longer span to shorter span  is less than 2 .

  In a singly reinforced beam, the effective depth is measured from its compression edge to  the centroid of the tension reinforcement .

  Spacing of stirrups in beams of effective depth’d’ should not be more than  0.75d or 300 mm ,  whichever is less.

  1)       As per IS: 456 - 1978, the pH value of water shall be  not less than 6 .

  1)      As per IS: 456 - 1978, the pH value of water shall be not less than 6 . 2)        Spacing of stirrups in beams of effective depth’d’ should not be more than 0.75d or 300 mm , whichever is less. 3) In a singly reinforced beam, the effective depth is measured from its compression edge to the centroid of the tension reinforcement . 4) An R.C.C. roof slab is designed as a two-way slab if the ratio of longer span to shorter span is less than 2 . 5) The value of the maximum strain in concrete under bending compression in outermost fibre, as per IS 456:2000 (Limit State Method), is 0.0035 . 6)   The minimum headroom over a stair must be 2.2 meters . 7) An R.C.C. column is treated as long if its slenderness ratio is greater than 12 . 8) The toe projection of foundation slabs is taken as minimum 150 mm or 1/5th of the depth of foundation , whichever is more (depends on site conditions, often approx. 1/3rd to 1/5th of...

  What is glass reinforced Concrete? Glass Reinforced Concrete (GRC) — also known as Glass Fiber Reinforced Concrete (GFRC) — is a composite material made of: ·         Cement (Portland) ·         Fine aggregates ·         Water ·         Admixtures ·         Alkali-resistant glass fibers 🔹 Key Features: 1.      High Strength-to-Weight Ratio – Lighter than traditional concrete. 2.      Excellent Tensile Strength – Due to the glass fibers. 3.      Durable & Weather Resistant – Good for exterior elements. 4.      Highly Moldable – Can be cast into complex shapes. 5.      Non-combustible & Fire-resistant – Makes it ideal for architectural cladding. 🔹 Common Applications...

  Q) Differentiate between singly reinforced beam and doubly  reinforced beam Aspect Singly Reinforced Section Doubly Reinforced Section Definition Has reinforcement only in the tension zone. Has reinforcement in both tension and compression zones. Moment Resistance Designed to resist only the moment that tension steel can handle. Designed to resist higher moments than singly reinforced can bear. Usage Used when the section depth is sufficient and moment demand is moderate. Used when section depth is restricted or higher moment capacity is needed. Steel Placement Tension steel only (at the bottom in beams). Tension steel at bottom and compression steel at top. Ductility Less ductile. More ductile due to compression reinforcement. Cost Econ...