Durability Properties of Ultra-High Performance Lightweight Concrete (UHPLC) with Expanded Glass

Abstract

It is important to ensure the durability and safety of structures. In the case of newly developed materials that are outside the current rules, it is important to investigate all aspects of structural safety. The material studied in the following is a structural lightweight concrete with an ultra-high-performance matrix and expanded glass as a lightweight aggregate. The material, with a compressive strength of 60–100 MPa and a bulk density of 1.5–1.9 kg/dm3, showed high capillary porosities of 12 vol% (ultra-high-performance concretes (UHPC) < 5 vol%). Since the capillary porosity basically enables transport processes into the concrete, the material had to be examined more closely from the aspect of durability. Freeze-thaw resistance (68 g/m2) and chemical attack with sulfate at pH 3.5 for 12 weeks (16 g/m2) showed no increase in concrete corrosion. Targeted carbonation (0.53 mm/year0.5) and chloride penetration resistance (6.0 × 10−13 to 12.6 × 10−13 m2/s) also showed good results against reinforcement corrosion. The results show that most of the measured capillary pores resulted from the lightweight aggregate and were not all present as a pore system. Thus, the durability was only slightly affected and the concrete can be compared to an UHPC. Only the abrasion resistance showed an increased value (22,000 mm3/5000 mm2), which, however, only matters if the material is used as a screed.

Investigations on lightweight concrete by in situ compression tests using high‐resolution computed tomography (μ‐CT)

“…Fracture pattern of a sample at 90 % of the maximum load and in the final state. The red frame shows the position of the 2D section in the 3D model (edge length 5 mm) 15 …”

“…The concrete used for the investigations is an ultrahighperformance lightweight concrete (UHPLC), which is described and characterised in detail in Umbach et al 9 In addition, Table 2 shows the composition with density class D2.0, which is presented in the results. All produced samples were demoulded after 24 h and stored at 20 • C and 65% RH until testing.…”

“…(A) Overview of the global coordinate system and the position of the sectional images, (B) overview of a CT scan with an image width of 5 mm 15 …”

A Systematic Review of the Concrete Durability Incorporating Recycled Glass

“…Figure 5 depicts the transport mechanism of expanded glass in ultra-highperformance concrete. The closed sintered skin of expanded glass interrupted the capillary pore system and thus the transport processes, making the material more resistant than NA to chemical or physical attack [53]. The permeability test is an important indicator of quality concrete in terms of water or oxygen.…”

“…[35] tested the sulfuric acid attack by adding FGA and CGA together according to the distribution of glass particles (0.15-12.5 mm) with different ratios, while Refs. [39,53] tested sulfate attack by replacing aggregates with FGA. It is noticed from the aforementioned studies that there is an improvement in chemical resistance.…”