One and Two Way Slabs Simply Explained

Olusola

One Way Slab

In reinforced concrete design, a slab is said to be one way if the length of the longer side divided by the length of the shorter side is equal to or greater than 2. 

With reference to the diagram of the slab shown below, If the length of the longer side (Ly) = 5m, and the shorter side (Lx) is 2.5m then 

Ly/Lx = 5m/2.5m = 2

On structural plans, the symbol used to identify a one way slab panel is shown in the previous diagram (symbol that the arrow points at).

In a one way slab design, the main reinforcement steel spans along the shorter side of the slab, which is also the span of the slab

In a one way slab design, only the two long supporting beams along the the long side of the slab  is assumed to carry the slab load equally between them. The beams along the shorter side do not carry any slab load.

For instance with reference to this diagram of a one way slab, beam 1 carries half of the slab load and beam 2 takes the remaining half, none of the slab load is carried by beams 3&4. This makes beam 1&2 the critical beams. Beams 3&4 will not be carrying any slab load, but may carry wall load and part of roof load. 

Two Way Slab

If the length of the longer side divided by that of the shorter side is less than 2, the slab should be designed as a two way.

With reference to the diagram shown, the length of the longer side, Ly, =6, and that of the shorter side Lx = 4.75. Therefore, Ly / Lx = 6 / 4.75 = 1.26. 1.26 is less than 2 hence the slab should be designed as 2 way.

The symbol of a two way slab is as shown above (the symbol that the arrow points at);

In a 2 way slab design, the main steel reinforcement spans both directions.

All 4 supporting beams carry some part of the slab load but the beams along the longer side carry more of the slab load than the beams along the shorter side.

The loading on beams for a 2 way slab is as shown. Note that the beams 1& 2 carry more slab load than beams 3&4

African World cup Qualifiers final Round Preview

Olusola
African World cup Qualifier Final Round

The first leg of the final round of African world cup qualifiers has been played. It is looking good for Algeria, Tunisia and Morocco. They all got good first round away results.Algeria downed Cameroon 1-0, Tunisia defeated Mali 1-0, and Morocco held DR Congo to a 1-1 draw.  It will now take a very determined effort by their respective opponents to overturn the outcome in the second leg. 

Although Egypt defeated Senegal 1-0 at home, Senegal, the current African Champions, is capable of overturning that result in the second game. 

Nigeria played a 0-0 draw with the Black Stars in Ghana. While Nigeria now have a slight edge as they play the second leg, they will be given a good run for their money by the Ghanaians.

How to make Puff Puff snack

Olusola
Puff puff

Puff puff is a very popular snack and very easy to make.

What you need to make Puff Puff:

Flour

Yeast

Sugar

Warm water

Salt ( optional)

Pepper/spicing (optional)

Vegetable oil

Frying pan

Cooker.

Quantities of ingredients

3 cups of flour will need ½ cup of sugar, one tablespoon of yeast, half teaspoon of salt and also half teaspoon of spicing.

Procedure.

Put about 3 cups of flour in a bowl. Add sugar, yeast and spicing. Mix the combination with warm water until a thick paste is produced. Cover it with foil paper and you can place it in a warm oven for about 30 minutes. After 30 minutes the mixture should have risen. Put a frying pan on the cooker and let it heat up the oil. With a scoop spoon or your hand, put small lumps of the flour mixture into the frying pan. Let them fry until their colour changes to brown red. There you are, you have just made your own delicious puff puff.

UEFA Champions League Quarter Final Preview

Olusola

Chelsea will face Real Madrid in the Quarter Final.

They met last season in the semis and Chelsea were 3-1 winners. Will history repeat itself?. Chelsea is now getting into form and will be very difficult to beat, moreover, they are the European champions. If Real wants to beat Chelsea, they will need to be at their best and not what we witnessed at EI Clasico.

Atletico Madrid take on Manchester City.

City should know by now that this game will be a highly tactical one. Atletico Madrid are specialists at eliminating English sides. It was United last time out and City could be next. Pep Guardiola will need to assemble a team that can overcome the frustrations Atletico will gIve them.

Benfica Vs Liverpool.

On paper, Liverpool should win this. But the champions league always has spring surprises. Benfica will play a giant killer role. This will motivate them to give Liverpool a run for their money.

Villarreal play Bayern Munich.

This game should be Bayern’s for the taking. But Villarreal  convincingly defeated the almighty Juventus in the second round. 

Uefa Champions League; All quarter Final fixtures

All Quarters final first leg matches will take place on 5-6 April, and second leg matches will be played, 12-13 April.

Buying , Using and Maintaining Tools

Olusola

Use the right tools to open up that machine or appliance.Use the right tools for the right job. Even the best quality tool is no good if it is unsuited to the job at hand.

For instance, trying to use a knife to turn a Philip head screw can lead to some difficulty. In some cases, it could even damage the screw head rendering it unscrewable.

It pays to buy the tools you need to open up an appliance. This is what professionals do. There are lots of low quality tools in the market, so beware. 

To make your tools last longer, give them good maintenance. 

Keep unused tools covered with a thin coat of oil. This can easily be achieved by putting a few drops on a clean rag and wiping it over the tool. Also apply oil on moving parts of tools such as locking grip pliers and adjustable wrenches.

Protect edges of cutting tools by preventing them from banging other tools. You can hang them on nails or pegboards. You can also place them in a protective cloth and put in a drawer

The English Premier League at Match Day 29

Olusola

Manchester City are still top of the premier league with 70 points. They dropped points at Crystal Palace after being held to a 0-0 draw. Liverpool who are presently in second place can reduce the gap to a single point if they win their game in hand.

Chelsea are third with 59 points and set to consolidate their position in top 4. They won a hard fought victory over Newcastle last time out and they are looking good.

Arsenal complete the top 4 with 51 points and 3 games in hand. Arsenal are in good form presently. 

Manchester United are 5th with 50 points. They must keep winning games to stand a chance of a top 4 finish.

Westham United have lost form, formerly in the top 4, they now occupy 6th on the table. It is almost impossible for them to make the top 4.

Watford, Burnley and Norwich City occupy 18th, 19th and 20th position respectively. They are in the relegation zone. Everton are not far off thanks to their better goal difference over Watford.

Spurs may end up mid-table this season. They occupy 8th position presently and are stable.

 Leicester City that occupied the top 4 almost throughout last season, find themselves in 12th position with 33 points.

As the premier league approaches the end these are questions that will be answered before then;

Will Manchester City retain their title?

Can Arsenal / Manchester United make the top 4?

Will Everton be relegated?