Lightweight and/or thermally insulating structural concretes having a higher resistance/density and/or resistance/conductivity ratio, and methods for the production thereof

A method of manufacturing structural and lightweight concretes, the method comprising:

• a. providing aggregates and a dosage of a binding matrix for the concrete, said dosage including a mixture of water and matrix cementitious material in a ratio of water to matrix cementitious material in a range from approximately 0.2 to approximately 0.5;
• b. providing an analysis of a plurality of lightweight aggregates by size fraction to determine a pore size distribution of each fraction;
• c. measuring a mechanical strength of the binding matrix;
• d. defining absolute and relative aggregate fractions according to the following function of pore sizes:
• for pore sizes of up to 10 μm, defining a minimum volume fraction of distributed air to be approximately 15%;
• for pore sizes of up to 40 defining a minimum volume fraction of distributed air to be approximately 50%;
• for pore sizes of up to 100 μm, defining a minimum volume fraction of distributed air to be approximately 75%;
• for pore sizes of up to 200 μm, defining a minimum volume fraction of distributed air to be approximately 90%;
• for pore sizes of up to 300 μm, defining a minimum volume fraction of distributed air to be approximately 100%;
• e. determining whether the following criteria are met based on the analysis performed in stages b) and c):
• i. a total volume fraction of air in selected lightweight aggregates is in a range from approximately 30% to approximately 99%;
• ii. a total volume fraction of air in the concrete provided by the lightweight aggregates is in a range from approximately 15% to approximately 75%;
• iii. a volume fraction of binding matrix is 50% or less of a total volume of the concrete;
• f. when these criteria are not met, repeating steps a) to e), and when these criteria are met, selecting the aggregates analyzed and the dosage for the binding matrix analyzed as the selected components of the lightweight concrete;
• and
• g. manufacturing a concrete with said selected aggregates, said selected matrix and said dosage.

A structural and light concrete, comprising:

• a) a binding matrix component having a volume fraction from approximately 20% to approximately 50% of a concrete total volume, the binding matrix component comprising:
• i. a Portland Type I, II, III, IV or V cement or a mixture thereof, according to ASTM C 150 standard, in a dose of at least 100 kg/m3 of concrete;
• ii. supplementary cementitious materials in a proportion of up to 4 times by volume of Portland cement;
• iii. a water component having a volume fraction relative to cement and supplementary cementitious materials in a range from approximately 0.2 to approximately 0.7;
• iv. a maximum volume fraction of calcium hydroxide (CH) of approximately 10%;
• and
• b) light aggregates corresponding to a volume fraction a range from approximately 30% to approximately 80% of the total volume of the concrete,
• wherein the concrete has a compression resistance, after 28 days of age, of at least 10 MPa, a density lower than 1.4 t/m3, a thermal conductivity lower than 0.288 W/(m*K) at 23° C. and 50% of relative humidity, and a quotient of density resistance Qσ/p of at least 17 (MPa*m3/t).