4.1.2 LWA

The LWA used in this study is Poraver, [19] which is an expanded glass granule. The material is pressure resistant, durable and dimensionally stable, 100% mineral, spherical in shape, ecological, and not hazardous to health. According to the Poraver technical data sheet, the aggregate is lightweight according to ASTM C330, C331, and C332 and DIN EN 13055-1. Mineral casting and polymer concrete, plaster and dry mortar, lightweight panels, automotive, 3D printing, and other additional practices are practical applications of this material. The aggregate sizes and properties of the LWA are presented in Table 6. The Poraver technical data sheet provided the absorption capacity and moisture content on delivery and specific gravity for the LWA [19].

4.3 Test methods

Figure 3.

59

Mix label

Table 7. Mix proportions.

w/c Cement (g)

Compressive Strength of Lightweight Concrete DOI: http://dx.doi.org/10.5772/intechopen.88057

> Water (g)

GM (g)

CS (g)

1 0.29 685 199 304 2545 — — 154 2 1.88 576 1084 658 1275 — — 2631 3 0.31 576 177 3284 508 — — 767 4 0.47 576 272 2631 1021 — 658 254 5 0.47 576 272 658 1021 254 658 — 6 0.7 576 404 1973 767 508 329 — 7 0.7 576 404 658 1021 254 658 — 8 0.47 576 272 3284 1021 181 — — 9 0.47 576 272 3284 767 167 — — 10 0.47 576 272 3284 508 253 — — 11 0.47 576 272 3284 254 340 — — 12 0.47 576 272 3284 340 421 — —

LWA LWA LWA

(1–2 mm) (g)

(2–4 mm) (g)

(0.25–0.5 mm) (g)

strength of concrete at days 7 and 28.

4.4 Results and discussion

Ultrasonic pulse velocity instrument.

ASTM C 192 was used as the guide for making and curing concrete test specimens in the laboratory [21]. The specimens were demolded after 24 hours and submerged underwater until a day before testing. UPV (Figure 3) and the axial compression machine (ACM) in Figure 4 were used to determine the compressive

In general it was observed that with increase in the amount of LWA in the concrete mixture, the compressive strength and UPV of LWC decrease, which was expected. In Figure 5, the relationship between UPV and fc (measured with ACM), at the age of 7 and 28 days for the LWC is presented. It can be observed that the results are scattered and more tests and specimens and concrete mixtures will be
