Particle size distribution was one test (done by sieving the dry soil though a set of sieves of increasing fineness -- using a mechanised shaker, rather like a paint agitator -- and recording the percentage of the soil that was stopped by each sieve), and moisture content was the other (done by weighing a fresh soil sample, thoroughly drying it in an oven, and re-weighing it).
For the concrete, a set of standard cylinders were taken for each pour, and at given intervals from the pour, one of the cylinders would be put into a hydraulic press and the pressure at failure recorded, yielding a chart of strength versus cure-time.
Bill