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 Planning, Laying Out, and Tooling Concrete Block.

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Presentation on theme: " Planning, Laying Out, and Tooling Concrete Block."— Presentation transcript:

1  Planning, Laying Out, and Tooling Concrete Block

2 Next Generation Science/Common Core Standards Addressed!  CCSS.ELA Literacy. RST.9‐10.3 Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.  CCSS.ELA Literacy. RST.9‐ 10.5Analyze the structure of the relationships among concepts in a text, including relationships among key terms (e.g., force, friction, reaction force, energy).  CCSS.ELA Literacy. RST.11‐ 12.3 Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks; analyze the specific results based on explanations in the text  CCSS.ELA Literacy. RST.11‐12.4 Determine the meaning of symbols, key terms, and other domain‐specific words and phrases as they are used in a specific scientific or technical context relevant to grades 11–12 texts and topics.  CCSS.Math.Content.HSGCO.D.12 Make formal geometric constructions with a variety of tools and methods (compass and straight edge, string, reflective devices, paper folding, dynamic geometric software, etc.). Copying a segment; copying an angle; bisecting a segment; bisecting an angle; constructing perpendicular lines, including the perpendicular bisector of a line segment; and constructing a line parallel to a given line through a point not on the line

3 Bell Work/Student Learning Objectives  Discuss how to plan and lay out a job.  Explain how to mix mortar and lay blocks.  Explain how to tool joints, patch holes, and clean smears.

4 Terminology  Batter boards  Block chisel  Block hammer  Block trowel  Closure block  Concrete masonry units  Corner block  Face shell mortar bed  Frost line  Full mortar bed  Jointer  Lightweight blocks  Mason’s line  Masonry cement  Masonry sand  Mortar  Mortar hoe  Raker joint  Standard or heavyweight blocks  Story or course pole  Stretcher block  Tooling joints

5 Concrete masonry  Popular type of agricultural construction.  Concrete blocks are strong, durable, fireproof, rodent and termite proof, and do not rot  Concrete masonry units, also called concrete blocks, come in two types and several standard sizes

6 General Types  Two general types:  hollow  solid  Standard or heavyweight block:  Made from Portland cement, water, sand, gravel, and crushed stone

7 General Types  Lightweight blocks:  Made from Portland cement, water, and lightweight aggregates, such as cinders, slag, or shale.  Weighs half as much as a standard block  Easier to handle but have greater insulating value

8 Block Sizes  Even number widths  4, 6, 8, 10, and 12 inches  Even number heights  4 and 8 inches  8 ×8 ×16 block  Widely used to build agricultural structures.  Actual dimensions are: 7 5 /8 ×7 5 /8 ×15 5 /8  Mortar completes the dimensions (3/8 layer)

9 Block Sizes  When the standard 3/8 mortar joint is added, the block with one mortar joint is 8 inches high and 16 inches long.

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11 Block Types  Building dimensions  Total length and width in inches should be divisible by eight so that full blocks and half blocks will be used  Blocks come in a variety of shapes  Corner block and stretcher blocks are the most common

12 Block Types  Stretcher block: has ribs on both ends  Usually with three cores or holes in the block  Used between the corners

13 Block Types  Corner block: Square across one end and has ribs on the other end  Used at the corner when laying blocks Use the dimensions to figure the  Use the dimensions to figure the number of blocks needed.

14 Other types of blocks!

15 Bonding Materials  Mortar: Bonding material made of sand and masonry cement  Mix one part cement to 2½ to 3 parts masonry sand.  Masonry cement: Type of cement used to make mortar while Portland cement is used to make concrete

16 Bonding Materials  Masonry sand is fine sand while the sand used in concrete is coarse sand  Use the following as a guide to calculate the amount of cement and sand to purchase:  in a 1:3 mix, 1 bag of cement and 250 pounds of sand will lay 100 eight inch blocks.

17 Laying out the Structure  Building must be laid out prior to digging the footing and pouring it  Surveying instruments  Easiest, quickest, most accurate way to lay out building’s corners  Generally laid out parallel to property lines or other buildings

18 Laying out the Structure  Surveying level and target rod: Helps to set square corners and the proper height of the foundation wall Dimensions should always be doubled checked Measuring for equal diagonals is a way to check for square corners.

19 If no Surveying Equipment  Establish a base line and use the 3–4–5 right triangle method to establish square corners

20 Outer Supports  Batter boards: Outside supports used to stretch strings  stretch strings: set up when corner stakes are in place  The batter board includes three stakes and two horizontal 1 x 4 or 1 x 6’s  The strings mark the outside of the foundation wall and the top of the foundation

21 Outer Supports  Plumb bobs can be helpful to insure that the strings intersect over the corner stake  Use powdered lime or spray paint to mark the ground for digging the footing

22 Outer Supports  Remove strings while the digging is done.  The surveying level and the target rod are used to set the grade stakes or forms in the trench

23 Outer Supports  The footing trench should be dug down to firm soil below the frost line  Frost line: Deepest point in the soil where the ground freezes in a typical year  The bottom of the trench should be flat and level  Most New Mexico building codes require the footing to be a foot deep.

24 Outer Supports  Footing rules are:  Set at or below the frost line,  pour a minimum of 8 inches for 8 inch blocks, 10 inches for 10 inch blocks, etc., and  have the footing at least twice as wide as the foundation.

25 Outer Supports  After footing is poured and forms are removed:  Sweep off the footing and re-stretch the strings  The plumb bob can be used at the string intersection to help mark the corners on the footing  This provides you with a straight line for laying the block wall

26 Outer Supports  Snap a chalk line on the concrete footing to mark the location of the outside of the first row of concrete blocks  Beginning block layers sometimes lay out the first row of blocks without mortar to make sure the layout was planned properly

27 Mixing Mortar and Laying Blocks  Good mortar: Absolutely necessary for good workmanship and a good finished wall  Process of laying concrete blocks requires considerable know-how and skill  Concrete masonry work may be contracted to professionals

28 Concrete Masonry  You start by mixing mortar and carrying blocks  Start with:  Clean, dry blocks  water  masonry sand  masonry cement  concrete blocks  quality tools

29 Mixing Mortar  Strength of a mortar joint is affected by:  Quantity of cementing material,  Portions and moisture content of the mortar, and  Quality of the workmanship.

30 Mixing Mortar  Mix one part masonry cement to 2½ to 3 parts masonry sand with enough to make a workable mix that is plastic enough to support blocks on a 3 /8 inch mortar joint until it has set  If masonry cement is not available:  Use Combination of Portland cement and hydrated lime

31 Mixing Mortar  Mix mortar in:  A leak proof box with shallow sides,  A wheelbarrow, or  A mixing machine

32 Mixing Mortar  To hand mix:  Use a mortar hoe (a hoe with two large holes in the blade) to dry mix the cement and sand until a uniform color exists.  Gradually add water and continue mixing with the mortar hoe until the mortar is plastic and workable

33 Mixing Mortar  If mortar is:  Too stiff: Will not bond well and results in a thick joint  Too thin: Will be squeezed out by the weight of the block resulting in narrow mortar joints

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35 Concrete Layout  Locate the corners and lay out the first course, without mortar, to check the layout  Full mortar bed: Using mortar on both horizontal and vertical cross webs of the block  Face shell mortar bed: Using mortar on only the horizontal cross webs of the block

36 Concrete Layout  Normally the first course uses a full mortar bed and the other courses use a face shell mortar bed  Always lay the blocks with the thicker end of the face shell up  This provides a larger area on which to place the mortar

37 Laying first course of Blocks  Mason’s line: Nylon string that is stretched tight to mark the top and outside edge of a row of concrete blocks  Once the first course corner blocks are laid in position stretch it so that the first course will be straight  Buttering refers to putting mortar on the end of a block

38 Laying first course of Blocks  Block layers often stand several blocks on end and butter the ends  To get a better bond to the block:  Flip mortar off trowel onto block with snap of the wrist  To place the block in position:  Pick it up with both hands and use a swinging motion to lower it into position

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41 Laying first course of Blocks  To make sure a laid block is level plumb, and aligned:  Use a level  Level the blocks by tapping the block with the handle of the trowel

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43 Laying first course of Blocks  Block trowel: Triangular shaped piece of metal with a wooden handle  Block hammer: Can be used to tap blocks into place as well as cutting blocks

44 Laying first course of Blocks  Block chisel: Three or four inch wide metal chisel that can be hit with the block hammer to mark and cut concrete blocks

45 After first course of blocks  Use face shell mortar beds and lay up 4 or 5 courses of blocks at the corners  Check for each block’s:  Level, plumb, and alignment  Checking horizontal spacing:  Use a straightedge or four foot level

46 After first course of blocks  Since each course is back spaced a half block, the corner of each back stepped row should touch the diagonally positioned straightedge.  Story or course pole: Board with markings eight inches apart  Use to ensure that the horizontal mortar jointing are running 3 /8 inches thick.

47 After first course of blocks  Key to a straight true wall:  Using the mason’s line between the corners as a guide  Most difficult part of laying blocks:  Usually laying the closure block

48 After first course of blocks  Closure block: Last block laid to complete the row  If vertical mortar joints have been 3/8 inches the opening for the last block should be 16 3/8 inches long (2 3/8 inch mortar joints and a 15 5/8 inch block)

49 After first course of blocks  Closure block:  Must be buttered on both ends or  Previously laid block must be buttered  If mortar falls off the end of the block as swung into place, block should be removed and re-buttered

50 Tooling joints and removing smears  Completes job resulting in a professional appearance to the job

51 Tooling Joints  Procedure that pushes the mortar into the groove between the blocks  Creating an improved bond of the mortar to the block  Results in a weather-tight joint with a neat appearance  Jointer: Concave or V- shaped metal tool with a handle and turned up ends

52 Tooling Joints  Brick layers often use a raker joint.  Raker joint: Tool that moves the mortar from the joint to depth of approximately 3/8 inches

53 Removing mortar burrs  After joints have been tooled, trim off with face of the wall with the trowel

54 Crooked Blocks  Do not attempt to move or straighten the block once the mortar has stiffened or even partly stiffened

55 Mortar Dabs  On block:  Should be allowed to dry  Use trowel to knock dab off  Piece of a concrete block to rub out remaining particles

56 Smears  When laying blocks, be careful not to smear mortar into the blocks  Once the smears are in the block it is impossible to remove them  A wire brush will help but is unable to remove mortar from pores in the block  Muriatic acid rinse will help clean the wall and make paint smears less noticeable

57 Review / Summary  Discuss how to plan and lay out a job.  Explain how to mix mortar and lay blocks.  Explain how to tool joints, patch holes, and clean smears.

58 The end!


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