I will remember to use the terminology that I pour cement as I don't 
really want anyone to mistake me for a concrete guy.

Often in NYC on the sidewalks the expansion joint material, which comes 
presized in height, is capped with an inverted light-gray plastic 
channel that is meant to be able to be pulled out later for the 
installation of a sealant. This could be described as tubular. Though 
concrete & sealants are different materials and technologies -- and 
therefore it is likely different mechanics or in some cases even 
different subcontractors would be involved. Quite often I see where the 
gray channel is not removed. My thought being that the concrete sub did 
his work and the sealant person never showed. Due to traffic more on the 
spiked heel level you can sometimes see where the tops of the channels 
is punctured.

In NYC there are contracts that the concrete folks bid on w/ the city to 
replace sidewalks. It is a low bid. When a property owner has a 
violation on their sidewalk they can opt to replace it themselves or to 
have the city engaged contractor do it. There are crews who do nothing 
but sidewalks over and over. A reason an owner would want to do it 
themselves would be like for an Alexander Calder sidewalk or for a fancy 
one like in front of the Ritz Carlton.

A seminal topic in NYC is replacement of bluestone sidewalks. There are 
the relatively small bluestone sidewalks in the brownstone sections of 
Brooklyn, then there are the occasional massive bluestone sidewalks in 
Manhattan. A few months ago I was asked to look at a sidewalk in 
Manhattan that had like 12' x 12' slabs of bluestone. This project sorta 
fell through the cracks for me as it is a hassle to custom order and 
deliver stone of that dimension and as a one-off endeavor our cost would 
be highly prohibitive... not hardly worth the time for us to figure it 
out. Need for boom truck, extensive permits, negotiation with quarrier 
where my experience is that they don't want particularly to hear about 
this sort hassle unless there is a lot of $$ involved. The client 
mentioned that their neighbor, NYU, had done over their sidewalk a few 
years before. If it is a large project it is inevitable that it would be 
done with union workforce (setters, laborers & derrikmen) incorporated 
into a larger budget... but to do 2 stones, and include in them cutouts 
for utilities, is not anything done out of a pu truck. The bluestone 
that quarries fabricate these days is not the same as it used to be in 
the old days. A lot of the smaller sidewalks end up replaced with black 
tinted concrete. Though bluestone sidewalks are neat they have their 
problems. They can be slippery in the rain, they move around with ground 
freeze-thaw, they delaminate, and tree roots like to push them around. I 
can imagine at one time someone sold them as superior to brick in a 
manner kin to sales of vinyl siding these days.

][<en

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