Concrete Block Test bench

Transcription

1 Item Code: Concrete Block Test bench Construction by stacking blocks TECHNOLOGY

2 A model/test bench To test and understand basic construction principles -How are buildings and structures built? - What are the characteristics of buildings where we are? -Why don t buildings fall down? Why are there different types of blocks? Real material Real appearance Scale 1:10 Grooved base to help set-up, to show why foundations are useful Why must the blocks be intersected? Why is there vertical chaining? Is it necessary? The role of the foundations assembly and dismantling using dry blocks, test different techniques, easily tidy the materials away at the end of class. How to build a structure? The different types of lintel

3 Concrete Block Test Bench March 2011 Etienne Bernot - Gérald Guillaume Published by A4 Company For more information contact: Technology Supplies Limited Phoenix House, Stafford Park, Battlefield Enterprise Park, Shrewsbury, SY1 3FE SUMMARY Test Bench General Presentation 02 to 03 Product presentation 02 Main teaching objectives 03 Activity 1: Build a simple wall using the blocks 04 to 06 Student worksheet 04 Example of student work 05 Student resource sheet 06 Activity 2: Build a wall using chaining 07 to 11 Resource sheet 07 Student worksheet 08 Example of student work 09 Activity 3: Installing a lintel 10 to 11 Student worksheet 10 Example of student work 11 Activity 4: Construction of a lintel 12 to 13 Student worksheet 12 Example of student work 13 Activity 5: Building a wall with a door and a window 14 to 15 Student worksheet 14 Example of student work 15 Activity 6 Extra Activity: Horizontal chaining 16 to 17 Student worksheet 16 Example of student work 17 Examples of information sheets 18 to 20 Activity 1 information sheet 18 Activity 2 information sheet 19 Activity 3 information sheet 20 Making mini blocks by themselves The CDROM The CDRom for this project is available in the Ste catalogue (Ref CD PARP ) It contains: - The folder in FreeHand (.FH9), PDF and illustrator (.ai) formats - Photos of the product, drawings in DXF format - 3D model with 3D files for SolidWorks, Parasolid et edrawings formats. This booklet and CDRom may be copied for students for internal school use* *This booklet may be copied as many times as necessary within school establishments for educational use only, on the condition that the publisher s name is included: A4. Copying or distribution for commercial use is not permitted without agreement from A4. Any copying or distribution of all or part of this booklet outside of school use is not permitted without agreement from A4. 01

4 Presentation of the Test bench Teacher document The concrete block test bench allows students to work on basic construction principles using stacked blocks. First the student builds a wall at an angle using a base as a foundation. The construction is then modified to include a window and a door. The building will be done with dry blocks so that material can be reused straight away. You can also use the the special mortar which is water soluble (Ref COL-BRIQ) if there is time (it has to be prepared, installed then left to dry). This allows in particular for the chaining blocks and the steel rods provided to build a lintel and test with or without an iron framework (If not you can use the wooden lintel provided). The test bench comes with: - 1 grooved base which acts as the plot of land with the function of a trench. - Blocks scale 1 : blocks 25 x 25 x 50 cm on the scale 1 : multifunctional blocks for chaining and table - 12 half-blocks, - 6 blocks of horizontal chaining and lintel - 1 doorsill - 1 window sill - 2 wooden lintels 25 x 25 x 150 cm on the scale 1/ 10-2 steel rods Ø 4 length 140 acting as reinforcement for the lintel framework - 2 PVC Ø 10 length 125 rods as vertical chaining bars for the window frame. - 2 PVC Ø 10 length 230 rods as vertical chaining bars for the door frame. - 1 PVC Ø 10 length 270 rods as vertical chaining bar for the wall angle. Base (x 1) (x 44) (x 6) (x 12) (x 6) Block 25 x 25 x 50 Multi-functional block Half-block Block Chaining (x 2) (x 1) (x 1) (X 2) (X 2) (X 2) (X 1) Wooden lintel Door sill Window sill Rods for chaining 02

5 Test Bench Presentation Teacher document Educational interest With some simple experiments, the test bench permits the following interests: building environment, technical functions and solutions, stability of a structure, building a structural model. It lets some functions and constraints be identified and tests some specific solutions of the concrete blocks. In the field of habitat and structures, students can learn about the following: foundations, chaining, functions of different blocks, wooden or cast lintels, technical vocabulary, bricklayer s tools. Other activities include the materials used to make blocks, industrial fabrication of concrete blocks, history of building with stacked bricks (history of concrete and its advantages). Useful links and support: Activities, changes The suggested changes are simple and quick to make; the blocks are easily dry assembled on top of each other. They can also be glued together using mortar (Ref: COL-BRIQ) available in our catalogue. In this case the time taken for the mortar to set should be taken into account during the activities Activity 1: By building a wall angle, the students will realise the need to have foundations and overlapping blocks in order to produce a wall which is sufficiently sturdy. They will answer questions and do some drawings. 03 Solution 1 Solution 2 - Activity 2: Students will learn about force and chaining. They could carry out experiments on the strength needed to destruct a wall depending on the chaining. - Activities 3 and 4: Cast a lintel with or without metal structure. Reflect on lintel construction and installation. - Activity 5: Build a wall angle with a door and a window. Learn some technical vocabulary. - Activity 6: Extra: Horizontal chaining Building very realistic models using mini-blocks The test bench can be used to create a very realistic model with mini-blocks using the scale 1: 10. Sets of blocks are available, as are moulds to make them yourself. See our offers in the catalogue or on The constructions are ambitious, very realistic and allow several experiments to be done, using a range of skills to solve real and simple challenges. The models produced can be kept as class materials for development activities or equipment (alarm, home automation). See page 18: Some useful materials 03

6 Activity 1 - Foundation and construction Student Worksheet Build a double wall that will act as a windbreak so that a barbecue can be installed. On the base acting as the foundation, put six rows of blocks (25 x 25 x 50) to make a wall angle as illustrated below. Experiment with different ways of stacking the blocks and find a way to test the wall strength. Wall of bricks Wall of bricks Base Base (concrete footing) Complete the following two sketches below to show 2 different ways to stack blocks Solution 1 Solution 2 What are the foundations used for? (represented on the test bench by the grooved rigid base) What are the qualities of a well-built wall and what tools should a bricklayer use? Describe how you tested the strength of two different walls and give your conclusions 04

7 Activity 1 - Foundation and construction Example of student work Build a double wall that will act as a windbreak so that a barbecue can be installed. On the base acting as the foundation, put six rows of blocks (25 x 25 x 50) to make a wall angle as illustrated below. Experiment with different ways of stacking the blocks and find a way to test the wall strength. Wall of bricks Wall of bricks Base Base (concrete footing) Complete the following two sketches below to show 2 different ways to stack blocks Solution 1 Solution 2 What are the foundations used for? (represented on the test bench by the grooved rigid base) The foundations allow the structure to be anchored to the ground and position the structure. What are the qualities of a well-built wall and what tools should a bricklayer use? The blocks must be well aligned, walls must be vertical. The top of the wall must be horizontal. The bricklayer will use a plumb-line, a level and a ruler. He will also use mortar to stick blocks together. Describe how you tested the strength of two different walls and give your conclusions We can see that when blocks are placed on top of each other without being intersected the wall is very fragile. However if blocks are intersected (the vertical joints are staggered in each row) the wall is much more cohesive, even without mortar, and is more resistant. To test the strength of the walls we pushed on them with a plate or a ruler to test the surface and not just one block. After several tries, we can estimate the compared strength of each construction attempt. 05

8 Activity 1: Foundation and construction: A bricklayer s tools Resource document The trough and trowel for the mortar Trowel for laying mortar The level to verify if the surface is horizontal or vertical The plumb line to check if the wall is vertical The laser level The rule to verify an alignment The pencil to draw marks The chalk line (blue) The chalk line string The hammer to cut and adjust blocks The cement mixer to mix the mortar 06

9 Resource document Activity 1: Foundation and Construction: Testing the Wall Resistance Two solutions to test a wall resistance Solution 1 - Cut a PVC plate using the dimensions below. 230 Ø Pass a string through the hole in the wall, pull on it as shown below. 115 Solution 2 - Hold a ruler at one end and use the weight to assess the pushing force on the wall. 07

10 Activity 2 - Construction and chaining Student Worksheet Here are the different blocks and the red PVC rods which act as the iron framework. The plastic rods replace the vertical framework block 25 x 25 x 50 multi-functional block half-block Carry out strength tests on the corner of a wall built with or without a framework (vertical chaining). See the drawing below. The wall corner must be rebuilt several times and test it until it is destructed. Explain how a framework can make a wall more rigid? You can interlock the PVC rods with the holes in the multifunctional blocks (in the corner) and the half blocks (at the ends).this vertical chaining joins various rows of blocks together and makes the vertical blocks at the corner and end of the wall very strong. The middle of each wall is weak but it is well supported by the vertical side blocks. Complete this drawing by drawing in the framework put in Two ways of testing the strength of a wall or 08

11 Activity 2 - Construction and chaining Example of student work Here are the different blocks and the red PVC rods which act as the iron framework. The plastic rods replace the vertical framework block 25 x 25 x 50 multi-functional block half-block Carry out strength tests on the corner of a wall built with or without a framework (vertical chaining). See the drawing below. The wall corner must be rebuilt several times and test it until it is destructed. Explain how a framework can make a wall more rigid? You can interlock the PVC rods with the holes in the multifunctional blocks (in the corner) and the half blocks (at the ends).this vertical chaining joins various rows of blocks together and makes the vertical blocks at the corner and end of the wall very strong. The middle of each wall is weak but it is well supported by the vertical side blocks. Complete this drawing by drawing in the framework put in Two ways of testing the strength of a wall or 09

12 Activity 3: Casting a lintel We have to build a wall like the one shown opposite, with a door and a window. Lintels are needed above the door and window to support the parts above them. The test bench includes wooden lintel and materials to make masonry lintels: chaining blocks and metallic rods used to make frameworks. Student Worksheet Load lintels To make the masonry lintels, the block chainings are placed side by side and are joined together using mortar that is poured into the gutter they form. For our experiments we will use the special mortar which can be re-diluted (ref COL-PARP). Think of and describe an experiment to prove the need for using a metal rod framework. Complete the following drawings (include a caption) and describe your experience. Filled in with mortar Mixing the mortar: 7 parts powder for 1 single volume of water Lintel 1 Lintel 2 What are the constraints or difficulties experienced? Complete the drawings to show the test to determine break strength. What conclusion can you make from our experiments? 10

13 Activity 3: Casting a lintel Example of student work We have to build a wall like the one shown opposite, with a door and a window. Lintels are needed above the door and window to support the parts above them. The test bench includes wooden lintel and materials to make masonry lintels: chaining blocks and metallic rods used to make frameworks. Load lintels To make the masonry lintels, the block chainings are placed side by side and are joined together using mortar that is poured into the gutter they form. For our experiments we will use the special mortar which can be re-diluted (ref COL-PARP). Think of and describe an experiment to prove the need for using a metal rod framework. Complete the following drawings (include a caption) and describe your experience. Filled in with mortar Metal rod Only mortar Mixing the mortar: 7 parts powder for 1 single volume of water Lintel 1 Lintel 2 Chaining block We made two lintels; one with a metal rod and one without. To test the resistance we will support the lintels on the exterior blocks and suspend an increasingly heavy mass on the middle block until it breaks. What are the constraints or difficulties experienced? The first difficulty was deciding the right amount of mortar to fill the lintels. The mortar needed to be pushed into the hollow of the lintel using a tool (a spatula or mini trowel) We had to wait for the mortar to set (one day) before doing the tests Complete the drawings to show the test to determine break strength. What conclusion can you make from our experiments? The lintel without the metal rod breaks under the strain of a 4kg mass. More than 7 kg are necessary to start to affect the lintel with a metal rod. The lintels with the rods are always more resistant, almost doubly resistant. Masonry lintels always have a metal rod. 11

14 Activity 4: Installing a lintel Student Worksheet Make a wall at angles with openings like the one illustrate?? Lintel Full part above an opening (door or window) What are the possible technical solutions to make lintels? Illustrate the two solutions on the drawings below. Explain what you need to do to be able to install a lintel directly from 3 lintel blocks. (You could prepare the ground lintels and install them once the mortar is ready but this would delay the construction and require lifting heavy masses). Illustrate your explanation on the drawing to the right, adding a caption if necessary.? How to support the lintel without mortar? 12

15 Activity 4: Installing a lintel Example of student work Make a wall at angles with openings like the one illustrate?? Lintel Full part above an opening (door or window) What are the possible technical solutions to make lintels? We have two possibilities using the material provided: Masonry lintels with lintel blocks or wooden lintels. Illustrate the two solutions on the drawings below. Explain what you need to do to be able to install a lintel directly from 3 lintel blocks. (You could prepare the ground lintels and install them once the mortar is ready but this would delay the construction and require lifting heavy masses). To be able to install the lintels, they must be supported with props, then insert the framework and fill with mortar. If the support is solid enough, we can continue the construction without waiting for the mortar to completely set and the full strength of the lintel. Illustrate your explanation on the drawing to the right, adding a caption if necessary.? How to support the lintel without mortar? Support board Support legs 13

16 Activity 5: Technical vocabulary Student Worksheet Work to do: Fill in the drawing below based on either the wooden lintel or the cast lintel solution and use the vocabulary resource table at the bottom of the sheet. Then complete the drawing using the correct numbers (Example 1). Use different colours to highlight the blocks that have a particular technical function: - the horizontal and lintel chaining blocks in blue, - the vertical chaining blocks in red, - the table blocks in green, - the window sill in yelllow, - the door sill in brown Other solution Wooden lintel Number Frame Sill Slab Door jamb Lintel Framework Opening Chaining Bay sill Apron Wall Name Lateral face, toward the opening, of a door jamb. Element located in the lower part and slightly sloped for drainage Foundation material made from strengthened concrete Vertical part of the structure, along a door or window Full part above an opening (door or window) Metal structure included in the construction to ensure strength Opening in a wall filled with a window Linking element surrounding walls. It can be horizontal or vertical A slightly sloped sill for drainage Wall element between the floor and opening support Definition 14

17 Activity 5: Technical vocabulary Example of student work Work to do: Fill in the drawing below based on either the wooden lintel or the cast lintel solution and use the vocabulary resource table at the bottom of the sheet. Then complete the drawing using the correct numbers (Example 1). Use different colours to highlight the blocks that have a particular technical function: - the horizontal and lintel chaining blocks in blue, - the vertical chaining blocks in red, - the table blocks in green, - the window sill in yelllow, - the door sill in brown Other solution Wooden lintel Number Frame Sill Slab Door jamb Lintel Framework Opening Chaining Bay sill Apron Wall Name Lateral face, toward the opening, of a door jamb. Element located in the lower part and slightly sloped for drainage Foundation material made from strengthened concrete Vertical part of the structure, along a door or window Full part above an opening (door or window) Metal structure included in the construction to ensure strength Opening in a wall filled with a window Linking element surrounding walls. It can be horizontal or vertical A slightly sloped sill for drainage Wall element between the floor and opening support Definition 15

18 6: Extra activity: Horizontal chaining Student Worksheet Use horizontal chaining blocks to build an eighth row. Use the metal rods of about 170 length or more for the chaining. To connect the horizontal chaining to the vertical one, you must drill the PVC Ø 3.5 bars at 185 and 190 from the end (See figure below). Chaining block 2 chaining steel rods Ø 3 length 170 mm Look at the vertical poles. Why do we make holes in them? Assemble the wall as shown below. Test the strength of the wall. What can you see? 16

19 6: Extra activity: Horizontal chaining Example of student work Use horizontal chaining blocks to build an eighth row. Use the metal rods of about 170 length or more for the chaining. To connect the horizontal chaining to the vertical one, you must drill the PVC Ø 3.5 bars at 185 and 190 from the end (See figure below). Chaining block 2 chaining steel rods Ø 3 length 170 mm Look at the vertical poles. Why do we make holes in them? The holes allow the vertical and horizontal chaining to connect. Therefore, the wall should become stronger. Assemble the wall as shown below. Test the strength of the wall. What can you see? We can see that the wall is much more rigid now, with the horizontal structure connected to the vertical one. The wall forms a whole, one part cannot be destructed unless all of it is. Everything is connected, which makes the construction very strong. 17

20 Activity 1: Foundation and Construction Example of information sheet Foundations. The foundation of a house or a structure corresponds to the part in contact with the ground. - It must receive and be resistant to loads that will press on it. It must not lose its shape too much. - It transmits these loads to the ground which must be as stable as possible. A study of this is therefore important before any foundation is built. Different types of foundation: Considering the above information, we can see that the foundation type will depend on the type of ground. Shallow foundations are used when ground is stable, otherwise deep foundations are used. Continue footing isolated footing Slab Posts or Well Construction technique: Stacking blocks to make a wall Concrete blocks are bonded with mortar 1: Overlapping blocks must be more than 1/3 of the block length. 2: The horizontal joint should be distributed on the whole contact surface 3: Vertical joints are made by filling gaps with mortar. A beam and post construction technique : Blocks are always bonded with the hollow part at the bottom. NO YES 18

21 Activity 2: Construction and chaining Chainings: They are made from metal rods embedded in the mortar. They let you link different parts or different blocks to ensure the structure of the house is rigid. Casted Post Example of information sheet Metal bars Mortar Vertical chaining Horizontal chaining Angle chaining blocks The chaining has several functions. When it s vertical: - It will ensure the wall has a certain mechanical rigidity, strengthens wall angles and the ends. - It will help the wall to support the load of elements above. When it s horizontal: - the load of the elements located above will be distributed across the width - it fights pressure on the wall (wind, beams) it stops the wall from opening - it also acts as a lintel above doors and windows. Horizontal and vertical chaining are connected in order to bind all the materials used in the construction. 19

22 Activity 3: Casting a lintel Example of information sheet Mortar The mortar is used to bond blocks together, like the two blocks in the example. It s a mixture of sand, cement and water. Mortar Mortar is particularly resistant to pressure but has low tensile strength. Reinforcement is added to the mortar (for tensile strength) to produce construction materials which need to have a good resistance to bending (slabs, beams, columns...). Mortar Metal rods Concrete is a mixture of mortar and gravel. The maximum concrete strength is reached progressively over time. It relates to the time taken to set, which depends on the cement used, weather conditions, the quality of the materials (sand, gravel) and their quantities. After 7 days, and ordinary concrete has reached 40 to 60 % of its final resistance (only!). and from 60 to 80% after 28 days. It s therefore not recommended to remove the formwork too quickly; the concrete slabs for example. It hardens when it s not moving (not because it becomes dry...) The cement itself doesn t have much resistance. It s the gravel, in the case of concrete, that gives some resistance (sand in the case of mortar). It s therefore of prime importance to choose good materials. RESISISTANCE TO COMPRESSION in MPa Hardening starts when it has set hour 3 h 5 h 24 h 28 days 91 days 20

23 Making blocks yourself As explained in the test bench presentation (page 3), it s possible to use mini blocks to make models. A4 can provide mini-blocks ready to be used but also materials to make them yourself. (Moulds, synthetic plaster, but also silicon fluid to make flexible moulds (indoor fluid, skin contact) Refer to the catalogue to see all materials and products available. Download Realizations in mini-bricks and Parpens and bricks models The mould. A flexible silicon mould to make blocks Ref: MOUL-PARP-A. The polyester synthetic plaster It is used as plaster but gives a very hard material that resists water. Dilution : 1/4 water + 3/4 powder. Before setting, the liquid mixture allows the moulds to be filled easily. It sets in less than 15 minutes. They are white in colour but they may be stained easily with a dye. Ref: RESI-PLAPE-1K25-BC. Black dye to colour the blocks Réf: COLO-N Sand mortar Mixture of sand and food resin that dissolves in water. It can be made into cement but presents no risks to skin and can be re-diluted in water, which allows you to recycle all the model s materials. Ref. : COL-BRIQ-5K Mini trowell. Réf. : TRU-MIN-9CM Mortar pan CUV-MORT-D13 21

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