Sure looks like portuclaca to me.
A great wed site is:
www.weedalert.com
Has a great data base and control suggestions

Don't think it's portulaca. Take a look at several images of chickweed.

Yep, chickweed...an evil, evil weed.

I think the leaves are too large to be chickweed and suspect it is "Portulaca oleracea", Purslane. The single best control of this plant is to grow a strong, vigorous turf. Seeds that will germinate into this are spread all over your yard by birds, same as with chickweed and many other "weeds". Mowing high helps a lot because that shades the soil so the seeds from these plants do not get the light they need to germinate.

Here is a link that might be useful: weed alert

Purslane looks like a jade plant leaf. At one time I would have said a small jp leaf but ones keeps getting larger and the other smaller in commerce.

It looks like chickweed to me. I have a seminary that has it growing on one of its ground fields. In early spring late winter the field from a distance looks like a carpet of blues ranging from the almost white to intense bright blue. A lawn person would cring seeing it but few see it other than the rabbits and deer.