Design of Pavement Lights
Design of Pavement Lights
(OP)
I am having to prepare safe-load and maximum-span tables for a series of reinforced-concrete pavement-lights. I am using BS 8110 for my design but I am also in the process of converting to Eurocode.
My problem is this. I have designed the lights as a series of one-way spanning beams with perfect lateral restraint. When I compare my results with Luxcrete's safe load tables for pavement lights (very kindly supplied by cds72); I do not get the same results: or even near them.
From my calculations, Luxcrete's span ratios for deflection exceed those permitted in BS 8110. Unfortunately, I do not have any case studies or standards to follow to compare my results with.
Has anyone any experience of pavement-light or small single-reinforced beams (Lintels?) that I could share ideas with. At these small depths of beam, do scale effects come into play? Did the authors of BS 8110 consider very small beams? I have not found any mention of small beams in the code.
My problem is this. I have designed the lights as a series of one-way spanning beams with perfect lateral restraint. When I compare my results with Luxcrete's safe load tables for pavement lights (very kindly supplied by cds72); I do not get the same results: or even near them.
From my calculations, Luxcrete's span ratios for deflection exceed those permitted in BS 8110. Unfortunately, I do not have any case studies or standards to follow to compare my results with.
Has anyone any experience of pavement-light or small single-reinforced beams (Lintels?) that I could share ideas with. At these small depths of beam, do scale effects come into play? Did the authors of BS 8110 consider very small beams? I have not found any mention of small beams in the code.






RE: Design of Pavement Lights
RE: Design of Pavement Lights
I am reading a text by Bernard Maidl on the subject at the moment and Maidl has shown that there is an improvement in crack widths (finer and more evenly distributed) but I have not found the amount of improvement yet.
However, when I check the span/depth of a Luxcrete pavement light with ribs of approximately 55mm wide by 110mm deep (giving an effective depth = 70mm with 10mm bar and 25 cover); The SD ratio for a 2950mm span is 42. I am not sure I could justify that ratio, even with fibre reinforcement.
Maybe pavement lights are not subject to BS 8110 SD ratios?
I was given this link by cds72 for Luxcrete span tables
http:
RE: Design of Pavement Lights
As well, glass embedments constitute a composite structure with the concrete. Except for the transverse ribs they (as long adherence remains high) must be enhancing overal tensile (and flexural strength). And trhough a complicated transfer of flexural solicitations, then you have the transverse rib to be for flexure a full rectangular section of the overall width, reinforced by the wires ... that the span/depth ratio suggest be prestressed.
RE: Design of Pavement Lights
I would expect that the luxcrete values are based on testing rather than code values.
RE: Design of Pavement Lights
Not sure if Luxcrete prestress.
I telephoned the technical department at Luxcrete and (this is from my memory - no litigation please) the calculations and testing carried out at Westminster University has been lost in a recent management re-organisation. I may consider approaching Westminster to see if the testing is in the public domain.
Am I able to model the pavement lights as a grillage in FEM? I know nearly all the properties of the material. I use PROKON for my modelling.