"And the mixing! Well, there was not much of it, just a turning over or two, and we deluged the stuff with water so as to make it easy to handle, and we hurled it into the foundations as we pleased and at all sorts of heights, just as might happen to be convenient. I did not trouble myself about it then, but I do now, for I had a month or two in and about the testing places when there was no other job for me that suited, and I firmly believe almost all the failures of Portland cement concrete occur because the men that used it do not understand it, or the specification is not carried out, or is wrong somewhere. The best goods in the world want proper treatment, and, after all, the abuse of a thing is no argument against its use. Some quarry owners and stone merchants don't like cement concrete; it is poison to them, because it hurts their trade. It is my opinion, founded on what I have seen and know, that Portland cement concrete is grand stuff when properly made; but you can't make the 'extra' profit on it you could, unless you can forget to rightly proportion the material. I mean leave out anything on the quiet you find is more profitable when it is absent; and now mixing machines are always used on works of importance where concrete is made in any considerable quantity, that is the only way you get a chance of a bit 'extra,' at least so runs my experience.
"Bless me! when I come to think of it, it is really wonderful that some of the concrete I have cast in has set at all, and don't believe it can all have set; for, first, the cement was wrong, then the gravel was not gravel, the sand was like road siftings, no trouble was taken to proportion the materials properly, and no mixing was done rightly, only an apology for it. The water was dirty, and used anyhow, and if a lump got a bit stiff it was rolled over, broken up in the trench and watered down below. Some went in like the soup that has balls in it, and we threw the concrete (?) down just anyhow. The inspector, as I said before, knew nothing much about it, although he was a beautiful kidder and could patter sweet and pretty just as if he were courting, and the engineer was away, so the road was clear for a bit 'extra,' and we took it."
"Now, how the dickens could any concrete be right with such treatment? It is cruelty to expect it."
"I left those works, and the engineer got corpsed, so he is past blaming; but, fortunately, the middle wall of the dock that got strained the most—the one in which was some of the concrete (?) I have been telling you about—had to be removed for improvements, and when they pulled it down I heard the concrete was in layers like thick streaky bacon, a layer of gravel with hardly a bit of cement in it, then a few lumps of solid on the top and hard as all would have been if the cement, gravel, sand, proportioning, mixing, and the putting into place had been done properly; then another layer of open stuff that had stuck together a bit, and then a lot of soft oozy rubbish, like decayed cheese, bad, coarse cement, you know, that would not or could not hold together and had done the 'fly' trick, you know, had cracked about, the coarsest part of the cement The streaks were there because we watered the cement so much that it was not concrete but weak grout, and bad too; and it could not drain down because one of the thin, hardish streaks, already set, stopped it, and it was bound to make friends with the gravel and dirt somehow, although trying to shun such company by running away and so get off duty. It was the same all the way through, and there were a lot of holes in it caused by the nearly set lumps coming together and slightly sticking, and therefore preventing the other material from filling the voids. Hardly a cubic yard of the whole mass was the same.
"That is what I call a real bit of scamping; but, honestly, I did not think I was putting it in so bad as that, but I then knew hardly anything about the material. I shall never do it again, for I know I shall not get the chance, besides we all must draw the line somewhere; but there, a lot is now known about concrete that was only in the brains of a very few then.
"As the cement is now supplied to you, I often put it in a bit thick, that is when I have to find the gravel and sand. It would be the other way about under different circumstances; but at the present time, with Carey's concrete mixer—which, luckily for plunder for us, is the only machine that measures and mixes the materials mechanically, and turns out from 10 to 70 cubic yards of concrete per hour—you do not get much chance of 'extras' and none with it; and concrete mixing is now nearly done as carefully as mixing medicine, and I don't regard concrete as fondly as I used to, for no 'extras' worth thinking of are to be made out of it. My old love, consequently, is cooling off, becoming warm and perhaps distant respect, not much else; but good Portland cement concrete is the best material, bar granite, I know of, if properly used, as it is then all the same strength—that is when the Portland cement is right, the proportions, mixing, and depositing even and proper, and the gravel and sand really clean sharp gravel and sand. You see, in that case, it is uniform throughout, and, after all, what is the good of the hardest stone or brick when you have a weak mortar to join them together which cannot nearly stand the same strain in any direction as the stone or brick?"
"You are right, it is simply waste. Like deluging good spirits with pure water, and spoiling them both. Lucky you had finally left those dock works before they pulled the middle wall down, or you might have had a bad quarter of an hour in a very sultry atmosphere."
"After that we will have a toothful neat."
"That's warming and is real comfort."
"I have never had much to do with concrete, but I remember seeing a lot go in on some dock works where I had some puddle to make for the cofferdam, and I got something 'extra' out of that."