Interlocking Concrete Paver Block
The construction of Interlocking Concrete Paver Block Road involves preparation of subgrade, sub-base and base course layers, bedding sand and eventually the laying of blocks. The block paving are often done entirely by manual labor . However, for efficient construction work, the manpower has got to be properly trained for this specialised job. Paving also can be done by mechanical means.
Preparation of Subgrade for Interlocking Concrete Paver Block
This is the First step on which the Interlocking Concrete Paver Block is constructed. Like in conventional pavements the water Level should be at a minimum depth of 600 mm below the subgrade.
Subgrade is to be compacted in either of 150 or 100 mm thickness as per 1RC:36-1970. The subgrade should be graded and trimmed to a tolerance of ± 20 mm of the planned levels, and its surface formed should have a tolerance of within 15 mm under a 3 m straight edge.
Base and Sub-base Course for Interlocking Concrete Paver Block
Base and sub-base courses are formed as per the standard procedures mentioned in the relevant IRC Specifications, like, IRC:37-2001, IRC:50-1973, IRC:51-1993, IRC:63-1976,
IRC: 19-1977. If cement bound base are proposed it should be constructed using rolled lean concrete as per IRC:SP-49. The quality control specified in IRC:SP-1 1 should considered. Constructing the layers to proper level and grade is extremely essential to take care of the extent and surface regularity of the block pavement.
Placing and Screeding of Bedding Sand for Interlocking Concrete Paver Block
The thickness of the sand bed after compaction should be within the range of 20-40 mm, whereas, within the loose form it are often 25 to 50 mm. it’s preferable to limit the compacted thickness to 20-25 mm surface level.
Bedding sand should not be used in the process to fill-up local depressions on the surface of a base or subbase. If any depressions then depressions should be repaired before placing sand. Sand used should be uniformly in loose condition and It should also have uniform moisture content. Ideal moisture content is which when sand is neither too wet nor too dry and have a value of 6 to 8 percent.
Requirement of sand for a day’s work should be prepared and stored beforehand and covered with tarpaulin or polythene sheets. The processed sand is spread with the assistance of screed boards to the specified thickness. The screed boards levellers are given nails at 2-3 m apart which when dragged it gives the specified thickness. The length of nail should take under consideration the surcharge to be provided within the uncompacted thickness.
Alternatively, the screed are often dragged jittery strips kept on each side as guide. Asphalt paver canbe employed in large projects. The sand is then compacted with the help of plate vibrators weighing 0.6 tonnes or more. Level checks shall be administered on a grid pattern to determine that the specified level is achieved. Local correction is often done either by removing or adding extra sand followed by levelling and compacting the layer.
There’ll be some settlement of sand after the blocks are placed and compacted, which must be allowed for, while fixing the extent of sand bed. The blocks will settle after trafficking in such a fashion that the surface profile becomes parallel to base/sub-base profile. Sand bed assumes uniform thickness under moving loads. Becomes parallel to base/sub-base profile. Sand bed assumes uniform thickness under moving loads.
Interlocking Paver Block: How to lay Interlocking Concrete Paver Block?
Blocks are often laid generally by manual labor but mechanical aids like hand-pushed trolleys can expedite the work. Normally, laying should commence from the sting strip and proceed towards the inner side.
When dentated blocks are used, the laying done at two fronts will create problem for matching joints within the middle. Hence, as far as possible, laying should proceed in one direction only, along the whole width of the area of the road to be paved.
While locating the start , the subsequent should be considered:
– On a sloping site, start from rock bottom poiht and proceed uphill on endless basis, to avoid down hill sneak in incomplete areas.
– just in case of irregular shaped edge restraints or strip, it’s better to start out from straight
– Influence of alignment of edge restraints on achieving and maintaining laying bond.
Interlocking Paver Block: How to lay Interlocking Concrete Paver Block Video ?
Compaction of Concrete Paver Block:
For compaction of the bedding sand and therefore the blocks laid over it, vibratory plate compactors are used over the laid paving units; a minimum of two passes of the vibratory plate compactor are needed. Such vibratory compaction should be continued till the highest of every paving block is level with its adjacent blocks. it’s not good practice to go away compaction till end of the day, as some blocks may move under construction traffic, leading to the widening of joints and comer contact of blocks, which can cause spalling or cracking of blocks. There should be minimal delay in compaction after laying of the paving blocks to realize uniformity of compaction and retention of the pattern of laying; however, compaction shouldn’t proceed closer than 1 m from the laying face, except after completion of the pavement. trafficked block pavements, heavy duty compactors should be used. After compaction by vibratory plate compactors, some 2 to six passes of a vibratory roller (with rubber coated drums or those of static weight but 4 tonnes and nominal amplitude of less than 0.6 mm) will further help in compaction of bedding sand and joint filling.
Joint filling of Concrete Paver Block:
The importance of complete joint filling can’t be over-emphasised.
Unfilled or partially filled joints allow blocks to deflect, resulting in loose blocks, possibly spalling the sides and a locally disturbing bedding sand layer.
After the compaction of the bedding sand has been completed (and some bedding sand has been forced up within the joints between blocks), the joints should be completely crammed with sand meeting the specified specifications, as given in Section 6. The joint filing sand should be stockpiled at suitable locations for convenience. There should be minimum delay in joint filling;the process should in any case, be completed by the top of the day’s work.
The operation of joint filling comprises of spreading a skinny layer of the joint filling sand on the block surface and dealing the sand into each joint by brooming. Following this, a far passes of heavy plate compactor are applied to facilitate fine sand to fill the joints. The sand should be broomed or cover the surface with alittle surcharge.
Dry sand and dry blocks are best for the filling of joint, as damp sand tends to stay at the very top of the joints; also, if the blocks is wet and therefore the sand dry, the sand will again stick at the joint top. Hence, if either the blocks or sand are wet, one may get a misunderstanding of the joints being full, but subsequent rain will reveal that they’re actually hollow. If the weather doesn’t allow sand and blocks to be dry, the joint filling sand should be washed in by light sprinkling of water. during this case, several cycles of application of sand, water-sprinkling and plate compaction are going to be necessary to completely fill the joints.
Bedding and Joint Filling Sand of Concrete Paver Block
Bedding sand : it’s well established that if proper attention isn’t paid to the standard of bedding sand, and if the thickens of the bedding sand layer isn’t uniform enough, serious irregularities in surface profile can result; excessive differential deformation and rutting can occur early in commission lifetime of the block pavement. the specified gradation of bedding sand should be as under :IS Sieve Size Percent Passing
9.52 mm 100
4.75 mm 95-100
2.36 mm 80-100 .
1.9.8 mm 50-95
600 micron 25-60
300 micron 10-30
150 micron 0-15
75 micron 0-10
Care should be taken to ascertain that single-sized or gap graded sands or sands with excessive amount of fines or plastic fines shouldn’t be used. the form of sand particles should rather be sharp instead of rounded, since the sharp sands possess higher strength and resist the migration of sand from under the block to less frequently trafficked areas.
Eventhough sharp sands are relatively harder to compact than rounded sands., the utilization of sharp sands should be preferred for the more heavily trafficked pavements. The bedding sand should be freed from deleterious materials.
Joint filling sand of Concrete Paver Block:
The gaps in between two paving blocks (typically about 3 mm
wide) got to be filled by sand relatively finer than the bedding sand. the specified gradation for the joint filling sand is as under:
IS Sieve Size Per cent Passing
2.36 mm 100
1.9.8 mm 90-100
600 micron 60-90
300 micron 30-60
150 micron . 15-30
75 micron 0-10
It is necessary to limit the fines (silt and/or clay) to 10 per cent, since excessive fines mak joint filling very difficult. Similarly, it’s not advisable to use cement within the joint filling sand which can not only make it difficult to completely fill the joints but would also adversely affect the specified flexibility characteristics of the paving block layer. The joint filling sand should be as dry as possible; otherwise complete filling ofjoints are going to be difficult. to beat the matter of efflorescence on the surface of paving block layer, the joint filling sand should be washed to get rid of soluble salts.
Opening to traffic for Concrete Paver Block:
Until all the joints are completely filled, no traffic should be permitted
over the block pavement. just in case of lime or cement treated layers within the pavement, it must be ensured that these are given a minimum of 14 and seven days respectively to cure, before traffic is permitted. The block pavement should be inspected frequently, to make sure that any incompletely filled joints, exposed by traffic and/or weather are promptly filled. Such frequent inspection should be continued till dust and detritus from the roadway tightens the surface of the joints.
Curves for Concrete Paver Block:
It is necessary to chop the paving units to suit the sting restraints. Rectangular blocks of an identical or contrasting colour as an edging are wont to minimise the visual effects of small errors in block cutting. To avoid unsightly and potentially weak construction joints, it’s often preferable to vary the laying pattern at the curve. The curve itself are often installed in herringbone bond and yet the pavement can revert to stretcher bond on the approaches.
Measurement of Interlocking Concrete Paver Block?
Interlocking Paver Block is measured in square meter. Labour rate for Interlocking Paver Block is inclusive of preparation of sand bed, laying of paver and joint filling with the sand.